ive read most of the post Bec from what i can gather you are doing eveything in your power so dont feel to bad. I have a now 3 year old DD we have a large family in saying this becouse of kaos we would talk for not to say this if what you have done but as a result DD wouldnt talk just grunt and scream yell and cry you can understand my frustration then she would bite not just any one just her older sister 17months older if she could nt get her point through she would bite for what ever reason we never really new but i think it was to defend her self against her older sister we never would bite back i would ask her would she like it if i bite her with my big teeth i would show her she would say no then i would explain why not to do it blah blah then time out it was a long process but it has worked i would make her kiss and cuddle her sister a say sorry it takes time make her use her big girl words i hope this helps
kath