My 12 week old is ebf but I'd like to start giving her the occasional bottle of expressed breast milk so that I can have a break from time to time. I've tried her a number of times over the past couple of months but have only managed to get her to drink from the bottle on two occasions. She will let me put the teat in her mouth, in fact she opens wide as if she wants it, but she doesn't seem to know what to do once it's in, she just plays around with it. Any tips?