Boyfriends mum hates me

Hi everyone, I don't really know where to start off but I have been with my boyfriend nearly 3 years now and his mum can't stand the sight of me. I work a very good job, I'm tidy and very respectful towards her and her family. Ever since we started dating she has tried to wreck the relationship telling him im only with him for his money and not to have kids etc 
How can I make her see that I am not a bad person and that I adore her son and cherish the ground he walks on.