Arrrgggggg...... I'm SO ANGRY

I had introduce teeth, gum and tongue cleaning to bernice since she was 6 months old. Every morning the maid or me will brush her teeth and gums with a two headed tooth brush (one side is normal brush and another side is rubber type for the gum), then we will use a white cloth to wipe her tongue. Everything was ok till this 2 months. She just refuses to open her mouth! When I try to clean for her she just scream as if I'm giving her medication. Oh what should I do? I tried stopping for 1-2 weeks then reintroduce it to her but failed. I tried having the teeth brushing together with her, failed, I tried using the natural enzyme tooth paste , she want to eat the tooth paste but refuse to brush! Everything doesn't seems to work.