1992 Ford Escort (automatic)

My daughter noticed yesterday that although her 1992 Ford Escort was running fine, it stopped wanting to shift itself into drive. When I checked the (automatic) transmission, the transmission fluid looked a light brown color with no smell. Her emergency brake light has been on (she now says about 4 months), but the actual brake is off. I drove the car a little bit myself and did not find an issue at the time. I decided to take it into the shop and have the transmission flushed, as well as the emergency brake light checked. Once the car was finished, the mechanic did not notice any other issue and stated that it was a little low on brake fluid and filled it which made the light go out. I test drove the car myself and it seemed perfectly fine. My daughter took the car and after driving it a little over an hour. She called distressed that it was happening again. I went and test drove it again. This time, I put it in reverse and it seemed to shift hard into place. I drove it around her apartment complex a few times without an issue, but after about 10 minutes.I was going to back up and I put the car in reverse, but the car would not back up or go forward when I put it in drive. The car was running fine, but you could tell that the car was not shifting into any gear. I turned the car off for a few minutes. When I started it back up, I was able to put it in reverse and then drive to get it back to her parking spot. But, as I made it to her spot, it was starting to do the same thing again. It does seem that the problem is temperature sensitive. Any suggestions would be most appreciated! Thanks!