my daughter has a 94 probe and when you drive it the brakes will engage, not lock-up butif you put the car in neutral it will stop

Jack up each wheel one at a time in rear and step on brake then immidiately try to spin wheel. If it has major resistance then you should be able to isolate the wheel in question. Oh yeah is it rear disc? If so I would say one of the calipers is frozen. If not you need to look into brake hose restriction also.

this problem happens after driving for 10-20 minutes

sounds like brake hose restriction then. Need to press back pistons in calipers. See if they press harder from side to side. If they do not want to press then crack caliper bleeder and press, it it goes back then you know which hose is bad.