What should I do?

Alright I need some advice. I am a mom of a 6 year old and 7 month old… I have been with my boyfriend for 3 years now. The older boy is not his bio son… For the first 3 years my in-laws were awesome with my older son, BUT the Christmas after the baby was born we went to my in-laws for Christmas which is normal, I had to leave right away and go home for the diaper bag which I forgot. When I got back my mother in law was showing me all the family pictures they took, all of the boys(including the baby) but not my older boy… completely left him out. So obviously I said something. The man I’m with is called dad and has wanted that since day one. But my mother in law went on this fit where apparently we aren’t family now because her son and I aren’t married. And that’s her excuse. Do you think it’s normal or am I being dramatic? This has been dragged on this long and now I have agreed to let her come to my home to see the kids, she did not say one thing to me. It made me so uncomfortable… I brought her drinks, and was as nice a possible the entire time. Should I say something else to her or just let another 6 months pass…