Either her or Rapunzel

Or Aurora

Most of her communication is not through speech anyways

She's very clever in these sort of situations, overcoming unexpected obstacles and such

Or Pocahontas

Tough pick, but interesting question. Let's assume though it's a permanent thing. As such:
- Jasmine is a strong willed, sharp, independent girl. She would be crushed at first, then she would likely start employing a personal set of charades nd the occasional scroll, driving people around her to understand her gestures at a whim. She'd still fare fairly well
- Belle is the more intellectually equipped: she's be likely to teach herself a proper sign language, and start teaching to similarly afflicted princesses
- Mulan would constantly risk being returned to the sidelined role a woman had in her society: eventually she's make herself heard, somehow, maybe acting stubborn sometimes
- Tiana would literally make her best with her body language
- Rapunzel would be likely the "worst": she's be a klutzy, albeit cute, mime. She won't lose her smile at all, but Flynn surely would get an hard time in understanding her
- Snow White would regret deeply her inability to sing, but in the end she'd adapt. However, she'd become a laconic kind of beauty, a woman of a few gestures
- Aurora and Cindy would likely follow Snow's footsteps. Cindy, however, would likely lean on her prince
- Pocahontas has already shown an uncanny aptitude at making herself understood. She'd be patiently trying to show the people she cares how interact with her, and she'd manage to without ever regretting her loss
- Merida would be literally pissed off, and for almost her teen life she'd become as noisy as she can to overcompensate. She'd try an exaggerate game of charades every time, comically failing