Not sure if this is really an etiquette question but here goes:
I have a large number of cousins on my Dad's side. They all got married 12-15 years ago and now have kids in the 4-14 range. Myself and my parents are closer with one branch- My Aunt (Dad's sister) and her two kids and two granddaughters.
All of the cousins' kids are invited, but I was wanting to send these two girls (9 and 11) their own invites. Their dad always treated me as an equal at family functions, even though I was 15 years younger (and the difference between a 10 and 25 yo is vast!) and I still remember I got my own invite to his wedding and thought that was just *the best*.
His girls are quite excited for the wedding, would it be 'ok' to send them both their own invite even if I don't send individual invites to all of the other cousins' kids?
For some background- we're not a 'close' family overall- we see each other at weddings and funerals. We live all over the country, so it's not like Sally in NH will see Ali or Kate's in VA invites or will talk to them before then.
Thanks!

Re: Extra Invites for Children
You know your family, though. Is there another set of parents who will be upset that their special snowflake doesn't get their own invite (but is still invited)? Do you care to deal with that drama? If so, id think about sending them to all kids.
I sent our niece and nephew (our FG and RB) separate invites, and separate thank you notes. Our niece loved it and felt very grown up. No one else knew, or if they did, didn't care.