Start slow & gentle with a silicone toothbrush. There is one called “baby banana”, it’s sold almost everywhere. Let her explore her mouth with it after you show her how to use it & describe how nice it is while you are gently brushing. Eventually, when you think she is comfortable with the baby banana you can then move up to a toddler toothbrush with soft bristles & a mild flavored toothpaste. We use Orajel Kids training toothpaste, natural fruity fun flavor. It’s fluoride free so it’s safe to swallow.

It's OK. Don't give up. Set a routine. We persisted with my nephew and now at 8 he doesn't miss his toothbrush. He needs help but long gone those tantrum filled nights. Even NT have sensory with brushing so perseverance pays off.

OT can help with tooth brushing. And… if you can and you find a willing dentist, take her to dentist 3-4 times a year and first two visits she just sits in chair and gets to know dentist and play with the equipment. I did that and now he tolerates dentist visits