It takes you by surprise that she asks you for that and at first you can't think of a name but when you go to ask her for some time to think about it a name appears in your mind: Jenna.
You don't know why but you know it's the appropriate name.
You think about putting yourself in the role of master and you say "Genie of the lamp I wish your name is now Jenna"
Formerly called Frank, she looks at you gratefully delighted with her new name. She will approach you to show her appreciation when something happens ...