I have a 89 Corvette that will go into reverse but will not move, not even a little bit, it drives great in all of the forward gears.

With such little information it is hard to say what happened. She was driving and heard a noise and now the engine runs but the car will not go forward or reverse. Several possibilities. The transmission problem or driveline-drive axle damage.

Can you get it into reverse with the engine shut off? If so, but you can't get it into reverse with the engine running, your clutch may not be fully disengaging. The forward gears have synchronizers that allow the gear to engage even if the input shaft is turning a little, but brakes keep the vehicle from moving.
If you can't get it into reverse even with the engine shut off, see if it will go into 5th gear with the engine shut off. If it goes into 5th but not reverse, you have an internal problem in the gearbox. If it goes into neither, your shifter linkage (or the shifter itself in the top of the gearbox) may need to be adjusted.

The question is a little vague but I think I know what your referring to. All modern automatic transmissions have torque converters. This is the device that connects the engine to the transmission. All vehicle manufacturers like the trans to be nice and smooth shifting. That's great but it does come with some minor drawbacks. If you are facing slightly down hill and you put your car in reverse but do not step on the gas slightly I can guarantee that you will indeed roll forward. You can eliminate that issue by holding your left foot on the brake while you shift into reverse. Then, as soon as you feel the trans engage, gently depress the gas pedal with your right foot and it will eliminate that forward roll problem.

May need to have the transmission flushed.
before you do that , put the car on a lift, raise
the car,run the car and switch gears while someone listens
for the sound for exact location.

it could be dirt/bad gas in the system(filter.carb)even though you used stabilizer.it could also be the trans sticking a bit and needs to be driven more.

It sounds like the shift lever is out of adjustment by a small amount. Try moving the shift lever a little bit forward & backward from it's normal position to see if this is the case.

Sad to say but your automatic transmission has bit the dust.

shift linkage needs adjusting,,could be bent, easy fix, located along firewall to fram beneath the column, ask your son wut he ran over and didnt tell u about... hope i could help...:)

are you sure it is first gear it is making when in 1. In park does the car lock up if you try to push it with the handbrake off. If not your problem is adjustment of the cable i.e. although the lever is in reverse the gearbox isn't.
Cheers John