I suspect it was a fairly small amount since, despite being an idiot in general, she at least knows that dish soap suds a lot. She's washed dishes by hand at least 5 or 6 times in her life I know for sure (mostly she has her men do things like that, she's got no time or energy for chores (or a job for that matter)).

I overfilled with regular dishwasher detergent once and triggered the overflow sensor. The dishwasher drained itself correctly, but bubbles in the little tube kept the float locked in the overflow position until they all popped, hours later. The soap residue left in the sensor bubbled up for several cycles afterward, repeating the problem. You can, theoretically, unscrew it from its mount and tip it forward to make the bubbles pop faster but that sounded like a recipe for disaster.

I cannot imagine what dumping regular-ass dishsoap would do to my dishwasher, but based on the above I'd probably just put a round in it and look for a new one.