Which name sounds better?

im writing a novel, and i cant choose a good name for her. her last name is Walker. i've already thought of Mio, Brandi, Felicity and Holly. She is blonde and just turned 14. she is nice and cautious, not too quick to jump into things. she is rich and lives in a mansion with both parents, brother and dog. (thats just some info about her) So i have another name in mind: Sheba or Sheila. i need opinions, which name sounds better?