Didn't her message say she can work for another 2 weeks? Seems awfully convenient that she's suddently put on bed rest. How does that work anyways? Bed rest with another little one around? She is going to risk less bringing her to daycare and going home to actually rest in her bed then she would making meals, chasing around, playing etc. You have nothing to feel guilty about. She can give 2 weeks notice and not bring her child, but still pay. That's called fulfilling an agreement. If her bedrest was that important and she was the kind of person that followed through on her word then she would do just that. She wouldn't risk her unborn child to fulfill 2 weeks notice just so she feels she's gotten her money's worth.

As far as addressing it on Tuesday, I think this ones a lost cause and not worth the stress of a confrontation. She hasn't done anything wrong except not pay you and that she is fixing by coming tomorrow to complete payment. She didn't bring her child to you sick, although it seemed like she threatened too. If by chance she stays with you and she does eventually bring the child sick, deal with it then and give a warning for not following policies.