Hi!
I live in the twin citities too (Plymouth) and found a painted turtle laying eggs on June 8th. I searched the internet and found a site that gives great instructions on what to do with turtle eggs. I did everything it said and dug up the eggs (so the raccoons wouldn't get them) and have been caring for them since. According to the website the eggs should hatch after 50 days depending on how warm they are kept. So I'm sure your friends will hatch this year. I know that sometimes if the eggs are layed later in the year, the hatchlings will just stay in the nest until the next spring. Next wednesday will be 50 days for my eggs and I'm really excited. We may do a live turtle-cam on the web while they are hatching! Here's that site and good luck -
http://turtle_tails.tripod.com/raisingbabyturtles/tour8.htm
Link