I am not going to assume that you have an nparent. I do, and I do not think OP, and those agreeing with OP, are overreacting.

My nmom made everything about her. If I got a gift from a friend, and it was something she liked, she'd expect me to give it to her. If I buy myself something, she expects me to buy her something too. If I tell a story, she will often interrupt me or find a way to make it about her.

She wants all the gifts, all the toys, all the compliments, and all the attention.

Do you have any idea how exhausting that is? To feel like you have no identity, no individuation, you simply exist just to cater to the whims and emotional needs of one person? Can't have anything nice, can't have anything that's yours, because they have to make it all about them.

It’s her child she raised her/him for 15 years I’m 100 percent sure she had no bad intentions.

How do you know that for certain? It's so important to assume a context of abuse and not assume what people have gone through. My mother raised me, and put together birthday parties for me. She was also physically and mentally abusive. Am I supposed to forget the abuse and show her love and appreciation because she raised me and threw me a couple of parties?