Sorry, this is going to be long!
DH and I got married last September. I have 2 DSs from previous and he has one DD - all of similar ages (12, 12 and 9). All 3 live with us. Because of COVID MIL has only met DSs a handful of times, likewise my brother and my dad have only met DSD a few times. My mum knows her better because she's stayed with us on holidays.
Since it became obvious DH and I were serious my family have always treated DSD the same as DSs in terms of birthday, Christmas presents. MIL not so much but DH always has an excuse for this.
Anyway, since DSs were tiny I've always done a photo calendar as a Christmas present for my parents. Since DH and DSD moved in I've included them in the photos and got a calendar for MIL too. All immediate family birthdays are on the calendar. My birthday was last July and MIL didn't acknowledge it at all, despite seeing her the day after it. DH didn't raise it with her as he didn't want to embarrass her and I wasn't too fussed as I'm way past getting offended about birthdays.
But it was DS1's birthday this weekend just gone and again, nothing from MIL, not even a card. MIL always makes a fuss of DSD on her birthday so it's not that she doesn't celebrate them at all.
Would you be hurt by this? Obviously I'm not going to make a big deal of it, but I do feel hurt and I don't know whether to mention it to DH. He's very defensive of MIL and I don't want to start WW673