SIL uninvited DCs to party

[Cocoadoodle]

SIL is having a big birthday party tomorrow night. It’s family and friends and has been booked for ages at a local venue with bar, disco.
Family are coming from different parts of the country, with some staying at other local family members homes and some staying in hotels.
We have 2 DCs, so SILs niece and nephew. DD 10, DS 7
This morning she’s nonchalantly messaged me saying oh no, just found out after speaking to the venue that kids aren’t allowed. I asked her weeks ago and she said they were! My DC are so excited to celebrate their aunts birthday and see their cousins/other kids from extended family, and now they can’t go and she doesn’t seem to give two shits! They’re going to be gutted.
Cousin (in law) is driving over after school tonight to stay at ours with her kids for the weekend, and SIL hasn’t even bothered to tell them that their kids are now not invited.
I know I’m not being U, but what are we supposed to do? Or maybe I am being U as it’s her party so she can do as she pleases.

I wouldn’t worry about talking to her about it. Dh just needs to say I hope you had fun, as no one will attend another of your parties.

Not the best reaction, I'll admit it, but I would not go at all and have a little "party" at mine with my kids and their cousins instead, maybe go to the cinema, a nice meal or something instead.

The SIL is clearly a bit thoughtless but I think the people calling her mum are pretty out of order. The SIL is 40 for gods sake - what is calling her mum to complain going to achieve apart from causing her stress.

The party was on Saturday.

I am so glad that you have posted this thread.
I am 41 and obviously you are never too old to learn new things.
Any party that I have been to, there have been children there. It wouldn't occur to me that some venues may not allow children for a private function. If that makes me thick, then I must be thick. I have never had to organise a big party and would expect a venue to make it clear upon booking that children are not allowed.

I am currently engaged and haven't even started looking at venues yet as the thought of it is so stressful. Taking into consideration the logistics. Ie, having it near my families location would mean some of DPs family not being able to come, and vise versa.
Now I know that I also have to make sure that children are actually allowed.
If I had booked somewhere and they didn't tell me that children are not allowed, I would be devastated. Especially finding out at the last minute. Not only would I be upset that guests couldn't come but also that my own child couldn't come.

I'm pretty sure SIL was told, or at least it was in the email but maybe she thought, oh it's just the official rules.

I think that's a pretty big assumption. Nobody knows if the SIL was told or if it's in the small print which SIL didn't bother to read.
With the way the op describes how the SIL was behaving, it sounds like SIL was genuinely looking forward to having the children at the party and it was a genuine oversight on her part or the venues.
I don't understand all of these posts that jump to the conclusion that it was malicious and was her intent all along or she only wanted to have an adult only party.
My point is that if I wasn't made aware that a venue didn't allow children, it's not something that I would have thought to ask as I would have assumed. That doesn't make me inconsiderate as that would make me inconsiderate towards my own child and myself and we would end up with a wedding party not attended by the bride and/or groom.
As it happens, I would be enquiring as to the suitability of the venue for multiple disabled children and that would be an opening for the venue to say that actually they can't accommodate children. If not for that, it wouldn't occur to me to ask about children in general.

Maybe malicious isn’t the right word, but I think it’s fair to say that it seems she didn’t want the kids there and possibly didn’t even want it to be a family party.

There was no food, she barely acknowledged her family and she and her friends essentially spent the night getting pissed.

It’s the kind of behaviour I’d expect for an 18 year old’s party, you’d think that most adults would have grown out of that kind behaviour by the time they’re 40.

With the way the op describes how the SIL was behaving, it sounds like SIL was genuinely looking forward to having the children at the party and it was a genuine oversight on her part or the venues. nope. It was clearly all an act.

Do you really think that someone who wanted children there and wanted a family party would have made no arrangements for food what so ever?

Just what kind of family party involving children is based around no food and everyone just getting pissed?

What did she expect? For the kids to just sit there drinking soft drinks and doing nothing?

Come on. Are people really that naive?

The more the OP has said about this party the more it was obviously planned this way.

I agree that the no food is being inconsiderate and a very bad host and that most people that are invited to a party would expect it to be catered. Maybe she just expected people would be happy to just buy snacks from the bar or had not even considered what people would do, especially those with children. Depending on what time the party started, maybe she just assumed that people would have their tea before attending the party. It was bad form for her to not communicate to people that there wouldn't be any food.
Not considering these things doesn't equal malicious intent.
She possibly just booked the venue and singer and cake and sent invites to the people that she wanted there including the children. Not realising that she needed to tell people that there was no food.
Maybe she wanted the children to come and is totally oblivious to the logistics. Maybe she was pressured to invite the children, didn't want them there so purposefully booked a venue that would exclude them. Maliciously excited the children and encouraged parents to lay out costs, knowing all along that she was going to break the bad news at the last minute.
All I am saying is that, I can see how it's an easy mistake to make as it wouldn't cross my mind to ask the venue about allowing children, and I would be mortified if I had made that mistake.

People are thoughtless and inconsiderate because they are. Not because they aren't parents.