It is completely inappropriate for your Dad Boss to be entering your room w/out knocking. Period. Even more so when you are already dressed for bed and in bed.

Definitely discuss this w/him stat. This should not happen again.

Regarding your charge, let her parents know that while you care for her dearly, it is not your job to sleep w/her in the same bed at night.

Stress to her parents that she needs to be told to stay in her own bedroom. No exceptions.