User blog comment:Omega natsu2/Chapter 355: Song of the Fairies, Predictions./@comment-4933386-20131004155909/@comment-7418318-20131004173824

Probably because she has to appear in some way for Lucy to get the full set of Zodiacs, at some point of the story.

But if Yukino somehow manages to convince Flare to join Sabertooth I'm going to throw up, gather the puke and mail it to Mashima.