Dd is 23 weeks and is teething, she has 2 teeth already and clamps down on anything that goes in her mouth including me!! I have tried lots of different thing but have decided to express and feed via a bottle except night feeds ( she never bited at night??? ) my question us am trying to introduce 1 formula feed so to ease the amount if expressing but she is refusing !! Can I mix formula with breast milk?? And what ratio ??