94 taurus will not go faster than 15 mph

Is the check engine light illuminated? Is the engine revving up or does it seem as if the engine is not performing correctly? Can you rev the engine in park? If the engine is functioning correctly, I would say that your torque converter has bitten the dust. Whens the last time the transmission fluid was changed?

we have just changed the fluid was changed today and so was the fliter. It will not go over 15mph. Do you have any suggestion that might help. I am a single mama of 5.

how many rpms can you get it up to in park?

If your engine won't rev up, you may have a plugged catalytic converter. If your engine revs to 6000 RPM easily (don't hold it there, just rev it up and let off the gas pedal), try diconnecting the battery for 10 minutes or so. If that doesn't help, you probably need a rebuild. Good luck to you.