Well behaved kids are welcome in most places in Maine but at the upscale places you may not want to bring them just so you can enjoy the atmosphere more)
In Camden the best is Bistro Francine (probably the best restaurant in mid-cast Maine) and also Natalie's is very good.
In Rockland go to In Good Company a great wine bar with excellent food I wouldn't recommend the kids here). Suzuki Sushi for what may be the best sushi in the state. Primo's is upscale and very good when they are on their game, just good when they aren't. Rustica for Italian/Med and Amalfi's for fusion Med. Go to the Sunfire Grill for good Maine style tex/mex.
In nearby Lincolnville you have The Edge, also upscale but on Sundays its pizza night and a family event. Very good pizza.
Otherwise there are tons of family places in Camden which you will see everywhere. Also the pizza at the Cedar Crest Inn is very good.
Don't bother with the Samoset. High prices for mediocre food. Had a good reputation for decades but was recently bought out by an international resort group and suffered drastically.
In Rockland the Rockland Cafe is basic NE diner foods but done well. It gets busy on the weekends, but very tasty seafood and breakfast and fries(hand cut)
Whales tooth in lincolnville is rather nice and While I have not eaten at the Samoset resort you should look into it as well. as this would be upscale.