I'm with
@hopeful on this one. I wouldn't put much effort into it and I or either my husband would call her up and ask what's going on. I'm more of a direct person though and don't like all the guessing and games.
Maybe she's having issues with the children? If they are boys, maybe she needs some male help and guidance with them. Maybe she wants his uncles to talk with them about safe sex? Maybe the kids are asking about their ancestry and she doesn't know how to answer? Do the uncles have a "relationship" with the children now, or maybe want one? Who knows, but the only way to know would be to ask.
I also wouldn't just show up, OP. Not without a phone call first. I would have my DH call and ask what's going on and that you're tagging along as well.