I'd say her, Merida, and Mulan.

She grew up with three loving aunts with no one to dote on but her. :)

or Aurora

I think Belle's father was always there to encourage her and comfort her when she didn't feel accepted by the surrounding town.

Definitely. She had both of her parents supporting her as an only child throughout her whole life as well as her grandmother. Even when she doubted herself, her father especially was very supportive of her. I’m kind of surprised that she’s so low in the polls.

^ I think she wasn't understood as well as they expected different things from her than she wanted to do, which sort lessens the support in a sense.
Merida has the most supportive system in place with both her parents love and guidance, house help, education, siblings love. Tiana and Mulan would be 2nd, as Mulan had family, looked financially stable and educated too. Tiana looked she had to struggle in her growing up years after her dad died although she had better family support in every sense.