how to change user account on iphone 4 without deleting voice memoos?

I had aa iphone 4 which i gave to my sister. Now she used it for a while and now she wants to sue her ownapple id to purchase and install apps. But she has some recordings in voice memos which she doesnt want to lose. There seems to eb some problem with phone and she cant take backup.

Now I want to know is there a way that she can change user account on her phoen and still doesnt lsoe voice memos? If yes, how?

Are vocie memos also tied up to the apple id on the iphone?