99 T&C Brake issue...HELP

Wife telling the brakes went out but fluid is leaking under center of vehicle when brake is pressed.
Is this just a rear brake line issue?

Most likely. Those brake lines have a history of corrosion problems. You'll have to get under there and confirm it. Don't splice in a new section. Replace the whole brake line.

I recall you ABS unit is close to the middle, and fluid may run a while before dripping. You'll need to get it on ramps and look for the leak while your wife presses the pedal.