User blog comment:Godofwar99/Erza, Princess of the dragons/@comment-30338537-20170108215453

Erza has no Dragon powers at all. This is due to Irene's Enchantments that prevented Erza from being contaminated, it even caused the birth to be delayed until Irene was willing to give birth.

The fact that Irene couldn't achieve any compatibility with Erza, eventhough they are related by blood, is further proof of Erza's lack of Dragon powers.

Besides, if Erza had Dragon powers, Acnologia would be on to her in a heartbeat. The reason he didn't detect Irene is a mystery to me, but she might've used some Enchantment or whatnot to prevent detection. Irene knows the terror of Acnologia and she likely tries her utmost to avoid becoming a prime target of his crusade. Erza on the other hand has no knowledge of Enchantments, grew up without any real knowledge of her own Magical power or Dragons and had never even heard of Acno until Tenroujima. So she couldn't have possibly figured out a way to avoid detection from an entity she knew nothing about.