K.S.
Hi E.,
I've been to Hot Sulphur Springs a couple years ago. I'm also planning another day trip there in March. It's a really nice, clean little resort. Prices are fairly inexpensive, $16 I think. The resort is set up in this kind of neat, quirky way. There are a couple swimming pools with the water in them, they vary in temp, that would be good for the kids. There are also a bunch of different little hot tubs and concrete pool that have the water in them of hotter temps for adults. Here is the link, so you can check it out. http://www.hotsulphursprings.com/
I've also been doing some checking and there are a couple little hotels in the town, along with the one associated with the resort. The resort one is most expensive, I think it was going to be about $100 or so for one night. The other two were between $45-55 for one night. If you get on a search engine and put accomodations for Hot Sulphur Springs in it, you'll find the hotels I did.
Getting there isn't too bad. You go over the pass into Winter Park, past the turn-off for Grand Lake. I think it's about an hour and forty five minutes or so.
I hope this helps! Enjoy your parents stay. K.