Threat to gate crash DD wedding

[Aussierelative]

Bit of background DSis lives in Australia and has been living overseas with her family for about 30 years. We keep in touch but are not really that close. We have not met in person for over 6 years and only every 3-4 years before that.
My DD is getting married in September. It is a fairly small wedding, 60 for the ceremony and wedding breakfast with another 40 [mainly friends] coming for an evening party. The decision was made months ago not to invite any cousins from either side. DSis and her DH are invited and have accepted although she made it clear that she was very disappointed that her two DCs were not included. They are both late 20's. My nephew is independent, but niece is still at home with parents mainly due to MH issues. I have heard a rumour that my DSis and BiL are planning to bring the uninvited niece with them presumably in the hope that we will somehow shoehorn her into the arrangements. My DH is fuming to say the least and never had much time for them anyway. He says that this is gate crashing and if they do this we should uninvite them even if they have travelled from Auz. I am not sure how to handle this. Any advice?

They don't have the spaces

I don't think you can bar adults from attending a wedding because they may know of "a legal impediment to why Fred and Fanny may not be joined in matrimony".
Attending the reception is a different matter, as it's a private party.

I think this is incredibly sad that your sister and her husband are willing to travel from Australia to attend your daughters wedding and you all begrudge their adult daughter who is struggling at the moment with her mental health, coming with them!

If I were your sister I would tell you all to shove it and I'd just put a card in the post.

For all the reasons that people have outlined on the thread.

I'm genuinely shocked that the consensus on the thread is that just because someone makes a long, expensive journey nobody asked them to do or even wanted them to do, you should uninvite someone from your wedding to accommodate them. I have a cousin in Australia. I assume similar to the OP's DD, we have literally zero contact. We got on fairly well at family meet-ups as children too - which is a more than the OP's DD and her cousin. He's a pretty much a total stranger to me now though, haven't seen or spoken to each other in over ten years. But apparently if he were to invite my parents to a wedding and I tagged along to Australia uninvited, I should be invited to the event above people he actually knows and has an ongoing relationship with! That's bonkers to me.

"They don't have the spaces"

for one person, or two people?

Seems a shame.

Sorry OP but when you say "it was decided not to invite any cousins" without any sort of deail or explanasion it seems like you're just being picky (no offense) and maybe there's more ot it than that. I just find it ridiculous how 40 people who aren't even family take precidense over people who are. I mean sure, you guys don't interact very often but considering you live 12 thousand miles apart and still make regular contact says this is a family member who'se dear to you. I wouldn't even blame them if they held a grudge agaisnt you for that...

But later on she says that some of the grooms cousins are invited, so one of those two quotes are a lie.

Only OP knows which!

It would be incredibly rude to turn up with an uninvited guest. It would also embarrass the poor girl. You have other nieces and nephews who weren't invited.

Op has stated that they are 60 spaces in the venue and they are accounted for. Should she now uninvite another guest because someone who hasn't been invited wants to come? Is this really what people would do

I don't think you can really play the "small wedding so we didn't invite you" card when there are going to be 100 guests!

Obviously if she's not invited, they'd be unreasonable to bring her.

But I think it's quite harsh to put your sister in this position. She lives halfway around the world, you're not just asking her to leave her mentally ill daughter for a few hours, you're looking at a week minimum. Either she goes without her daughter, which is pretty crap even without the mental health concerns ("oh yes dear, dad and I are going back to the home country to see all our relatives and probably some friends too, but you can't come") or she brings her daughter along and awkwardly ditches her to go to the wedding.

I find it so strange that people would invite their own brother/sister but not their niece/nephew. Weird

Yes, but then you just explain to the aunts and uncles who can inform the cousins that one cousin was there because of the special circumstances of living with her parents and coming from far away and that she just turned up.

I would just tell the venue on arrival that one extra person has invited themselves. It's unlikely they'll make one person leave. It's like if you book a table at a restaurant and someone brings a friend without telling you. It's rude and the restaurant might be annoyed, but they will accommodate you.

I don't think my DM did. She had about 9 cousins and my DF had some too and it just would have been too much I suppose.

Definitely for a church wedding, but at a private venue? The legal impediment thing is only tradition now as we can easily search whether someone is already married.
When was the last time it was used except on TV?

How much does she like her aunt and uncle?

Good idea to FaceTime. Best to chat things through rather than message, which can lead to misunderstandings and assumptions.

When they’re travelling from the other side of the world for the wedding, and it’s their first trip back in 6 years, it’s a big deal and they perhaps thought it’d be nice for your DN to come too and all catch up with you all. They may well have accepted she won’t be able to attend the wedding.

I don’t think it matters what your DH thinks. They’re your family, not his. In terms of the wedding, it matters what your DD thinks as it’s her wedding. But hopefully, your sis will stay after the wedding and you (on your own if necessary) can have a good catch up once all the prep is out of the way. Best not to let a partner distance you from your family just because they have no time for them.

Couldn't agree more.

They might, but at our wedding venue it was strict numbers and we had to confirm food choices etc. There were no extra meals so that would be an issue.
It's also just really rude to invite someone who hasn't been invited

Definitely at a private one. Assuming it is a properly licensed venue. See my earlier response to another doubter.

What other requirements are there for premises?

• You must ensure the public have access without charge to the ceremony room(s) for one hour before and during the ceremony.
• There must be access for disabled people.
• Notices are required at each public entrance giving directions to the ceremony room(s), names of the couples, time of wedding and room of wedding so that the public can find the venue easily.

People have different family set ups and dynamics, it's not that hard to understand.

I suppose I do understand it ,but would hate it to be my family dynamic

This is maybe touching a nerve because we had a huge issue at our wedding with my PILs inviting all manner of 'family' who had travelled from very far away without asking or telling us who were turned away by the venue, but people who are saying to just invite her/add one more person/fit her in - have you no concept of how wedding venues work?? *
*
Generally, you pay per person, and the venue will have really strict rules about maximum guest numbers. You can't get round the rules as weirdly, the venue staff can count and will notice too many place settings. Not that OPs daughter should, because it's her and her DPs wedding, not the OPs, or the OPs sister, or her next door neighbour, or her fourth cousin on her dad's side.

Because the venue has a cap on numbers.