The 2011 Sorento's mileage wouldn't be a deal killer for me if it was in good condition and checked out by a mechanic. The mileage is rather high for the age, but that usually means the majority of miles driven were on the highway. Highway miles cause much less wear than city miles.
The 2012 concerns me for a couple of reasons. First of all, you didn't specify that it was a V6. If it has the standard 4-cylilnder, that would be a deal breaker for me. I've driven a few Sorentos with AWD and the 4-cylinder and it's simply not enough power for that size and weight of vehicle (especially with a full load of passengers). Having two owners in 4-5 years isn't always a bad thing, but I would take a closer look at the specifics. How long did each owner keep the vehicle? If the second owner quickly traded/sold the vehicle, I'd be concerned. Most of all, the accident concerns me because it happened so recently and you aren't certain of the severity. If a car is wrecked and traded shortly afterward, that's a bad sign! Personally, the vehicle's history is questionable enough to keep it off my list.
An alternative that you probably haven't considered is the Mazda CX-9. For $15k, you could get a 2010-2011 CX-9 Touring (or Grand Touring, if you're lucky) with reasonable miles and in good condition. The Touring model has standard leather seats and is basically loaded (power liftgate, moonroof and Bose audio system were options). I have a 2012 CX-9 Grand Touring FWD that I bought new in November 2012. It currently has 63k miles on it and I am still in love with it! It looks great, rides smoothly, handles far better than any mid-size/large crossover should and has plenty of power. Reliability appears to be good overall, with the front brakes (warped rotors, which I solved with $250 aftermarket high-performance rotors) are the main problem area. In general, my 2012 looks and feels more like it's one year old rather than almost four?.a great vehicle! At least take a test drive in one.
The question of whether to keep your 2003 Odyssey is one that only you (and possibly your mechanic) can answer. You mentioned that repairs are getting expensive. What repairs have been done and what (if any) current problems need to be fixed? How many miles are on it? Would you feel comfortable taking it on a 500-mile trip? Some people advocate driving them until the wheels fall off (literally and figuratively). That may make the most financial sense for a single person, but when you factor in a family, it's a different story. A 14-year old vehicle simply isn't going to be as safe as one that's 5-6 years old. There's also the risk of more and more repairs (things you never even think about can start breaking as you approach the 15-year mark). If you have a transmission failure, major electrical issues or engine trouble, it could easily cost $3-4k or more. Good luck and please let us know how it works out!