Michelle has a slender figure and is of average height. She has a striking resemblance to that of Lucy, having wavy dark blonde hair, blue eyes and fair skin. Her attire makes reference to upper-class women consisting of a pink and white themed dress with a white trim and a red ribbon attached to it in which the top of the dress is a lighter pink while the area below her waist has a darker shade of pink and a pink bonnet also with a white trim that has a blue corsage on the left side. Michelle wears white stockings and little red shoes.
Michelle is a dedicated and passionate person, searching for Lucy for over seven years, in honor of Jude Heartfilia's wishes. She is often seen being cheerful, smiling sweetly when around others. Michelle notably also seems inspired by the guild and how they tackle missions, mentioning that it seems like a fun place to be in. She often has a very clumsy side to her and tends to be quite sensitive and fragile, often crying loudly whether from happiness or sadness. According to Lucy, there is something about Michelle that makes everyone want to protect her. Michelle has a sporadic appetite; she is often seen eating food when talking to others. Happy had also remarked that Michelle similar to Lucy as they were both noisy. She also shows a side of interest to her, unafraid to watch a potentially dangerous mission right in front of her and also takes action immediately when she sees Lucy in danger. 
Little is known about Michelle, but according to research done by Laki, it has been stated that the Lobster family was a wealthy plantation family concentrated in the Zentopia Church Parish. It has also been found out that she was, and possibly, the only survivor of a event linked to the Zentopia Church and the Legion Corps.
Key of the Starry Sky arc
Note: Events in this arc occur only in the anime and do not constitute canon material.
Arriving by train, she enters the Fairy Tail guild where Romeo points to Lucy. She introduces herself to Lucy who does not even know her. Mortified, she blubbers up emotionally hurt. Furthermore, Michelle shocks Lucy and her friends when she addresses her as "Nee-san," as -san is the sign of respect for someone older and Lucy didn't think she was older than Michelle. She mentions that her family and the Heartfilia family are distant relatives to rectify Happy's misunderstanding of Lucy's father having an illegitimate daughter. Michelle starts to sob until Lucy asks about the case she is carrying. She then attempts to embrace Lucy, but Michelle unfortunately drops the case on her toe. Moments later, she informs Lucy that she was instructed by her father to send that case as a memento from him to Lucy. Jude also requested for Michelle to search for Lucy during that 7-year gap. Afterwards, Natsu tells Lucy to open the case. Inside, Lucy and the others, puzzled and filled with wonder, find a bandaged key-shaped object. Carla, at the sight of the unraveled, mysterious, key-like object is somehow terror-stricken. Everyone else is curious about this shady memento and question about it. Michelle tells everyone that she hasn't eaten in three days.
By the river, Michelle follows Lucy to her house while carrying Plue in her arms, and Lucy tells her how much she loves her guild. Michelle compliments Lucy and states that Jude would be proud of her. In Lucy's house, Michelle gazes at the photos of Jude and Layla and then reads Lucy's newest script for a novel. When Lucy comes back, she finds Michelle crying about Iris. Michelle expresses her envy for Lucy who has big dreams while she has none. Lucy decides to let Michelle stay here. Michelle starts crying again, and Lucy tells her to get a job here at Fairy Tail guild. A montage of Michelle helping her guild is shown while Lucy narrates. With the montage over, Natsu calls Lucy for a job to catch some bandits, and Michelle gets excited because she wants to see Lucy in action. Even though Lucy doesn't want Michelle to be there, Makarov and the others insist that she brings Michelle with her; Erza reasons that Michelle will get experience. Lucy vows to protect Michelle as the gang head out for their mission.
Somewhere in Fiore, Gray goes over the mission, but Erza comes with the cart and a plan involving her and Lucy being decoys while Natsu and Gray attacks the bandits by surprise. However, Natsu refuses to ride in the cart which prompts Michelle to volunteer as a decoy. As Michelle and Lucy drive the cart down the path, Erza and Gray wait in the back with Natsu and Happy soaring in the sky. Michelle and Lucy arrives to a blockade where the bandits greet them; Lucy immediately executes Erza's plan by showing off her body. Somehow, the bandits are not aroused by Lucy's curvaceous body. When the bandits decide to rob the cargo, the men find Gray attractive and tries to assault him. Though, Gray and Erza attack them. The boss appears and freaks out Lucy and Michelle with his strange behavior. He attacks Lucy, and Michelle attempts to help her; Natsu appears from the sky and defeats the boss.
With the mission over, Lucy and Michelle eat lunch, and Michelle proposes to make a request to solve the mystery behind Jude's memento. At Fairy Tail guild, Lucy gets permission, and Natsu takes on Michelle's job. Then, Michelle trips with the memento falling on the ground. Suddenly, the object levitates with mysterious runes or characters revealing itself on the object. Makarov tries to tell Lucy to give up on the request, but Lucy insists on solving the riddle for Michelle's sake. 
Deciding to research into the memento, Lucy and Michelle start by looking at different books. Michelle asks if she found anything yet, but gets no for an answer. Later, at a festival, she is enjoying the food being served and asks Lucy to try some, but Lucy replies that she doesn't want to. Later that night, she is in Lucy's appartment, discussing the mysterious rod with Lucy and Levy. She is shocked when she hears that the rod resembles one of the hands on an ancient clock.
Michelle hears Hughes saying that they came to capture Lucy Heartfilia. Michelle listens as those three tell the guild that they will take her by force. Michelle watches as the Guild and those three fight. Michelle notices that Lucy is going to reveal herself but before Lucy can, she steps forward instead, stating that she is Lucy, shocking the others. When Lucy states that she is Lucy, Michelle puts on a performance, stating that Lucy is Michelle trying to protect her. Michelle starts an argument with Lucy, with both claiming to be Lucy. When the guild distracts the enemies, they tell Michelle and Lucy to escape and find the master. 
Michelle and Lucy decide to take a rest at a nearby tree. Michelle is scolded by Lucy for putting herself in danger and trying to take her place, but also being thanked for caring enough to do so. She and Lucy start to discuss if the trio were responsible for the church attacks until Coco finds them and demands Lucy to come forward. When Lucy points at Michelle for being Lucy, she plays along and confuses Coco. Virgo suddenly appears and helps them and Coco gets distracted even further. They take the chance to run away. Michelle and Lucy are later found by Earth Land Hughes, who controls Michelle with her Magic and prepares to make Michelle throw herself over a nearby cliff. Lucy grabs Michelle to try and stop her, but Hughes' Magic forces Michelle over the edge, with Lucy and the metal rod falling with her.
Main article: Lucy Heartfilia
Michelle calls Lucy "nee-san" and is her distant relative. Despite not knowing her, Michelle was looking for her for a long time in order to deliver her father's last gift. Though initially surprised, Lucy later accepted her and even offered her to live with her, an offer that Michelle accepted. Lucy also feels that there is something that prompts her to protect Michelle though Michelle herself is willing to risk her safety to save Lucy as seen when she charged the bandits during one of Team Natsu's missions.
Main article: Jude Heartfilia
Jude was Michelle's uncle and the two had worked together in the past. The two had shared a close relationship as Michelle was at his side during his dying moments and was dedicated and loyal to him as she was willing to go search for his daughter in order to deliver his last gift, even to the point that she would not eat for days at a time.