I figured out the problem. The image mode was already set to RGB, but if I click on the View menu and click Proof Setup, and click RGB in there it clears everything up. The weird thing is that it was set to CMYK when I went in there and I switched it to RGB. But when I opened it with another file my wife made it already had RGB checked, yet the problem was still there. In spite of it already being checked, though, clicking on RGB still fixed the problem.
Anyway, just thought I should throw the solution out there in case anybody else ever runs into it.