"I can't be found out... I don't want to make Mira-nee and the others sad again. I have to hold it in! I will live out my life in Edolas" That's what she yelled at you when you asked her to come back to Earthland. It sounds like she wants to be alone, but after some fighting and convincing, she came back and decided to apologize to you.

"I'm sorry that I didn't want to come back..."