OP, as long as she shows up
on time on her scheduled day and does a great job w/your children, then what she does in her
spare time should have no bearing on you.
She is young. At her age, she is enjoying doing things that young girls do. Young girls can stay out, yet have the energy to work a full day on little rest the night before.
If she is not showing up, or showing up looking hung~over or strung out, then
yes, it most definitely would be an issue for me.
But if her extra curricular activities in
no way affect her work performance, then let it be.
Remember:
She is your
employee.....Not your child.