Again, this is just my opinion - but now I have thought about it some more, I think she is doing you a disservice by bringing the 'mother' angle into it at all. She does some wonderful, precious things for you, but in my mind it is damaging for you, with your pain and your past, for her to hang this relationship on a mothering framework. Her poor choice of words ('like a mother') cheapen the profound care she has for you, imo. If I were you, I'd be agonized and confused, because I'd see how much she genuinely did care, but it would feel like she was playing mummy to me like kids in the playground, lightly picking it up and setting it aside on a whim, not quite realizing how deeply these isolated acts of 'mothering' affected me.

I'm answering from a position of someone who lost my wonderful mother who adored me utterly to cancer, when I was twenty five. So my loss is a different kind to yours, which is the 'never having had a mother'. Perhaps my kind of mother-pain is located in such a radically different place to yours I struggle to understand, so maybe that is skewing my perception, but I don't know.