I think she might be a little frustrated at the difficulty you have trusting and being open with her.

It's understandable on both sides (her frustration and your reluctance).

When I was a child anything nice that was done for me was immediately then used to point out what an awful person I was (i do X for you and you can't even do Y. You are a bad person).

It took awhile to start trusting that people could care and do so without strings. It was also hard for me to not feel like I was being set up when people do nice things or care. Just kept waiting and/or creating the next bad thing they would do.

What if you took a moment and entertained the idea that she was pointing out the money to show that she cared? Not as a method to point out how ungrateful you were, but to point out concrete ways in which she was showing you that she cared.

Perhaps it was a way to provide evidence that SHE is willing to put her money where her mouth is, so to speak.

What if she doesn't expect you to do anything except he happy and open to the fact that she does care?