Chihiro. She went through literal hell to save her parents, so you know she'd look after you.
Satsuki and Mei are cute, but Mei is a toddler and I'm not big on toddlers. Plus you can't take one and not the other when they're as close as they are. Kiki would be a fine choice too. The Laputa girl who's name I can't remember might be OK, but she had a lot of people chasing her, which translates to a lot of trouble for me. Shizuku is a published author (The Cat Returns is clearly one of her works), so she'd be another good one.