Upload & Sell: Off
In this industry, where everyone is a photographer, and everyone can do it "better" and cheaper than you, you have to let this go. People will steal the images off of your blog. They'll edit them with instagram and stupid filters on their phone (just had this happen to me). Then they'll upload them to Facebook and, hopefully, not tag you (also just happened to me). They'll not give you credit (also just happened).
They'll hire another photographer 2 months later. Maybe they want variety. Maybe they want a different style. Nothing wrong with that. If I could have Jonathan Canlas shoot some portraiture of my family, Katy Merry shoot my wife nude, Jeff Newsom shoot my vow renewal, and someone else shoot my kid, I'd do it in a heartbeat. I love variety.
I had a bride and groom get pictures taken 2 days after their wedding at Disneyland by another photographer. I only gave two teasers the day after, but this photographer had almost all of her images up the night she shot. Well, I had 3000 images to go through. She probably had 200. Not fair, right? I was confused people would think SHE shot the wedding and I wanted what's mine. MINE MINE MINE MINE MINE. Sounds like a childish reaction, right?
But hey, seriously, who cares? Maybe she was a friend. Maybe she did it cheap. Maybe they just liked her work. But clearly, I wasn't 370 mile away in Disneyland when they wanted pictures taken. And turns out, the photographer is really nice and I've chatted with her a bit.
TL;DR - let it go.