When the parent comes the next time you explain that you are terminating care for ... And list your reasons and then hand her a written letter in a sealed envelope explaining that due to lack of compliance of your illness policy and a general air of disrespect towards you and your business you are terminating care on what ever date ....two weeks or what you have set out in your policy.
Take a photocopy of the letter for your records. If you want to term immediately then bring up the face book thing because I would be furious if they blantently got my whole family sick and all the other daycare kids