Perhaps she is trying to get rid of you guys and this is her way of showing it? Maybe she's just as peeved at you for taking over her house as you are at her for not doing her bit.
You'll never know unless you all discuss.
Maybe she thinks along the lines of 'fine, you can live here but don't expect any help from me'. I guess that's her prerogative (if that's the right word).
Not saying that she's right and you're wrong, just saying perhaps look at it from her perspective..