Obviously You are the one who first attacked her and bitching about her pronouncation (Look, you even bitch about it here). It doesn't sound like she is complaining everyday until up to one point you couldn't take it so you lessoned her. NO! You are the one who's bitching about it, not Her! 3 months, maddam, from a total non-english environment to an english environment; I think it's a good job for her already to try communicating with the customer service people, that's a start! at least she is not forwarding her "responsibility" to you.
I suggest you to leave your friend, coz more likely you are the one who's preventing her to gain confidence with her existance in an English country. How can someone gets the courage to try, if a person like you aside keeps bitching about everything.