For those who asked if it was just tone or if she specifically said something that blamed me/DH, it was hard to tell. She said something like, "Julia bit into the soap, and found out it tastes nasty." Someone said, "What?" and Julia's mom replied with, "Well, Julia didn't know what it was, since she's never seen a bar of soap before and there wasn't any liquid soap for her to use".
Also, Mom wasn't in the bathroom with her; Dad was in the bathroom with her and Mom went to go see what happened when the unearthly shrieking/crying/yelling combo broke out. Dad's comment was something along the lines of "I don't think she'll ever do that again".
One more comment - the soap was not decorated/scented in anyway to resemble specific food. It's shaped like a hockey puck, maybe about 3 inches in diameter, tinted a very faint pink, and smells kind of floral and fruity all at the same time. I actually made it myself when I was experimenting with how much madder root I needed to color white soap (a lot, as it turns out).