That's really a sh**ty situation lol If it were me, I would let them go for lying. Did they flat out say he was going to be one when he started? That would make me VERY angry and I would let them go. Also, the fact that mom would want ME to follow HER schedule wouldn't fly with me either.
I know you just started, I just started a few months ago, but you're going to be in for a big surprise if you allow people to push you around like that. I would definitely be letting them go simply for lying. JMO