Sister in law and my bridesmaid didn’t show up for me or her brother, and I’m trying not to be upset about it. Just need outside perspectives!

Hi everyone! My wedding was this past Saturday August 17, 2024. It was beautiful and other than some small hiccups, it was a perfect day! However, I can’t help but be hurt by my new sister-in-law and her husband’s actions. It was mostly child-free, but my husband’s only sister has two children under the age of 3 (one is 9 mo, and the other is 2.5 yrs) and he insisted on having them as part of the wedding. We had one other little girl in our wedding close to us, but otherwise the youngest kid there was 16. My new sister in law is a helicopter parent, and her husband doesn’t appear to be much help. However, they have a full time live-in nanny they brought with them, and my feeling is that a professional nanny should be able to handle two children for a couple hours while they take one night off. She has been with them for over 2 years. The husband was also a groomsman after he was upset that he wasn’t originally invited to be in the wedding party. Both kids are pretty under-socialized and predictably had meltdowns in the cocktail hour, so all of them left, and they didn’t come back for the entire remainder of the reception. They missed dinner, toasts (my dad had a whole heartfelt speech prepared to their family), our first dance (which was a choreographed salsa dance we have been preparing for for months), my husbands’ dance with their mother, and everything else aside from the ceremony itself and part of the photos. I didn’t get pictures with my entire bridal party because she left photos early as well. My mother in law needed her daughter with her too. They were also over 30 min late to the rehearsal because they couldn’t gather themselves. I’m struggling with trying not to be angry with them for taking care of their children in the way they see fit, but I just can’t accept that the nanny alone or at least the nanny and father could not handle the two children for another 1.5 hours while she should have been there for her brother. This whole process has had an immense amount of effort put into it, and I just feel like their actions indicate they didn’t really care about it. She didn’t even tap me on the shoulder to say “I’m so sorry but I have to go, congratulations” or even text to apologize afterwards. You have to put your kids first, but sometimes you also have to make sure you don’t miss life because of them. Just wondering what people would feel about this situation, and if you would bother speaking up about it. I told my husband I was hurt by their actions, but he would never tell his sister that. A quarter of our wedding party was absent because of them.