My Mom and I always were close, and we still are. I always remember her birthday. She almost always forgets my birthday. I am usually mildly hurt, but I will never let her know that. I know she cannot afford to give me a present, but a card, or even a phone call will suffice. My brother's birthday is a few months after mine. A few times in the past she has asked my help to pick up my brother a certain present, usually one that is "shown on TV" , and use my charge card to buy it for her, and then she will pay me back. I usually decline with some excuse.
I feel it will do no particular good to tell her that I've been hurt. My Mom is now 83.