You'll need to look into the green card problem before anything else.
My mother is a U.S. citizen and it took me 12 years to get a green card, if I was sponsored by a sibling it would have been longer.

Google Visa priority date, I just checked U.K citizens sponsored by a sibling and they are processing applications from 2003. It would be the F4 category. Your wife would be the primary applicant and you and your children would be derivatives. There is talk of eliminating this category but if you apply now you will be grandfathered I believe. It doesn't hurt to submit the application, I had actually forgotten about mine it had been so long.

Good Luck