What kind of name would you like for her? An English name, a Japanese one, or another language? (I recommend that her name match the language of her voicebank.) Is there a meaning you’d like the name to have? If Japanese, are you looking for an actual surname, or a made-up name? (Ex: the names that end in -ne (音) or contain kanji related to singing or music (ga 歌 is also commonly used). Many people are tired of the -ne names, but I am personally fine with it.)
If you give me a bit more info, I can give you suggestions!
Edit: also some useful links about UTAU naming
here (UTAU wikia page on naming),
here (about Japanese names) and
here (general UTAU design advice).