Offer to make changes she wants.

After considering for a moment, you realize that this curse could easily be a gift to Maisie if it were used selflessly. You could remain true to your friendship and her trust by never using her curse against her, or for your own selfish gain.

"Hey, Maisie. I just realized. I could be your personal genie!"

She looks up from her phone at you, puzzled, and says "What?"

"Well, you told me about this curse so it would never be used against you. But, what if I used the curse FOR you. You could choose something you want to change about yourself, and I can make that change for you, leaving you in complete control!"

She pauses in thought for a second. "Well, I have always wanted to . . ."