Mememum, of course we do not think you are a useless mum. Please don't think that yourself! How horrid of your Aunty to make such a cruel and thoughtless comment (she obviously isn't raising toddlers at the moment).
You are just like the rest of us - trying to do the best we can with unexpected, frustrating and difficult situations that arise while raising children.
Actually, handlemecarefully, I think your suggestion is a good one (can't do any harm to try anyway).
Does DH overindulge her? If so, you will forever be seen as the boring parent, while he is fun! Also, how does he react to her saying such things? In our house if DS says something rude to me, DH immediately has a stern talk with him, explaining that what he said is not nice and that it can make me (or whoever it is aimed at) unhappy inside. Perhaps you can use her idol-worship of your DH to your advantage. Get DH (if he'll help) to explain to her that when she is mean to you, it is the same as being mean to him. And that you and he are a team, and if she ignores you or yells at you or whatever, that it makes him very sad. (You haven't really said, but it seems like you are not getting the support you need from DH. He needs to let her know that her actions are not ok). Also, I think it is very important for you DH to be demonstrating his affection and love for you. If she sees him hugging and kissing you - then she will get the idea that you are important to him (we do this and at first DS freaked out and yelled "no hugs, no hugs!" We extended the hug to include him, but never let him come physically between us during our embrace. We wanted him to know that we are a team, and as important as he is, there is no divide and conquer in our house). At two you can explain some of this to them and let them know what you expect from them.
Not sure if this has anything useful on it. Dr Phil is a trained psychologist and seems to really be able to help people with problems in their families/parenting. I was sceptical at first, but have applied some of his techniques with my DS with fantastic results. Ignore it if it is not your thing. Just thought I'd attach the link in case.
BTW - remember that you are here on MNet putting yourself in a vulnerable position, asking for help for your situation. To me that says you are an excellent mum who loves her child and will go to great lengths to do the best for her.
Take care of yourself.
xxx - sorry about long post!