Same as the other's said. Don't pin her down again - that'll make it worse. One day of missed brushing isn't going to be the end of the world.
DS1 still sucks and chews and he's nearly 3.
Try letting her brush your teeth, or use your brush, or DH's. Make it fun. Sing sings, poke tongues, brush teddies teeth, brush each other's teeth. Do it together if possible because we know they just love to copy mum and dad and make sure she knows it's going to be a ritual everyday. Eventually she'll be joining in.