Try giving her the toothbrush in the bath and see how she goes. Also let her do it and don't make a big fuss over it. Miss M has times when she brushes like crazy and then just wants to eat/suck the toothpaste the next. A doctor friend of my mums has a 2 year old who hated brushing her teeth and she was so worried but after speaking to another professional they said just let it be and eventually she would come around. 3 weeks later she was jumping for joy as it just happened. We have also had a trip to the dentist (chipped tooth in the bath) just recently so I also remind her that the dentist said she had to brush her teeth. The other game we play is that one of her imaginery friends (Buzz, Woody, Maisy who ever is the flavour of the day) sits on the side of the bath to see how she brushes her teeth. Probably not much help now but when your 16 month old is a bit older it may be easier to communicate what is happening. I also stand behind Mackenzie when I do give them a brush and ususlly it is only an option for about 10-15 seconds before she pulls away.