2 Weeks is a long time to be sick, and to be off work to be home with a sick child. If it's that serious to be off for 2 weeks then you need to be aware of the sickness in order to warn or prepare for it to spread around the daycare. So, either she's not telling you what the little one has (maybe hand foot mouth, maybe chicken pox? ) and that's a serious no no in our business. Or, she's pulled out and is not coming back. This is where a 2 week deposit for the final 2 weeks of care would have come in handy.

Move on, look for another client. If this one decides to come back let her know that you need payment before you can discuss future care, when/if she gives you payment then hand her a termination letter. Go ahead and replace. The chances of you getting paid for those 2 weeks are very small at this point I think. You're best to cut your losses and move forward.