I thought 15 hours of printing was lost. I searched the forums for what this error meant, and it turns out that the thermistor that reports the bed temperature had come loose. To protect itself and our home, the printer aborts whatever it's doing when this occurs. I took the bed off, fixed the loose bed thermistor, reassembled everything, and recalibrated the bed. I'm glad I took the photo of the failure screen because it told me it was printing at 61mm layer height when it aborted. Since it aborted the print and didn't make spaghetti of everything I went back into Slic3r and cut the model again at 61mm. I then decided to print the remaining pieces separately:
Once finished, I had 4 parts instead of 2. Oh well! I glued the parts together with CA, and started printing the lid.
The lid is supposed to stick into a receiving hole in the bowl, but there's no way for it to flip up or down. I made a quick pair of supports for hinges in TinkerCad, cut off the tab from the lid and made a hinge pin from some T-pins. After adjusting the fit, I glued the hinges to the bowl with CA.
My daughter is super excited to have a potty for her doll. It only took a couple bucks in plastic and a few days' work. Yay daddy!