Yes, there is single track, and yes family trails. The centerpiece trail of the area is a 35+ mile long trail on an old railroad bed that follows the Lehigh River in a scenic gorge. That trail has mostly families and people who ride moderately. Don't be fooled if that is all the pics you see, the place is not really marketed to the single-track rider anymore.
The "anymore" means the Jim Thorpe area went through a change several years ago, in that some of the popular technical and single track trails were deemed off limits to MTB-ing. That was because some of the trails were on (partly or mostly) what is called State Game Lands (state lands used for hunting funded by sales taxes to hunters and hunting). And unless the trail was specifically deemed open to MTB-ing, it was considered closed to MTB-ing. That was statewide on all State Game Lands, not just in the JT area.
But not everything is closed. The land in the area is a mix of State Game Lands, State Forest Land, State Parks, plus county owned land (in parks and just raw land). The only trails ones that were closed were the ones on State Game Lands. That's the good news.
The bad news is JT has not done a very good job communicating how this worked to the bike riding public. They have nice pics or families riding on the main rail trail in the Lehigh Gorge, but beyond that, even long term residents of the state and some locals are not quite sure what is open and what is not. I'm in that category (long term residents of the state ... not quite sure).
I used to keep up with it all, but the uncertainty turned me off in the last few years, and now I go elsewhere. If you ask at the two local bike shops (both sell maps), they will be able to tell you exactly. Some locals on here also keep up with what is open and closed. To summarize, there is a mix of easy (family), intermediate, and very technical. And you can ride to all of it from the very center of the downtown.
The next few weeks will be nice there, with the leaves changing color, and the cooler and drier fall weather. And it will be before hunting season gets into full swing in state.