The new girls love being new (working) moms!
Fox — who shares two sons, Noah, 3, and Bodhi, 2, with ex Brian Austin Green — joined the cast as a guest star while Miz Deschanel was on maternity leave.
The 29-year-old Transformers actress totally gets what it's like returning to work after giving birth:
"It's tough. You feel like a lot of mother's guilt, having to leave [your child] all the time and then at a certain point, I had to just release that and go, 'There are my kids, these souls came through me for a reason, they're gonna be bonded to me no matter what and this is a part of life. I have a job, I have to have a job.'"
The single mom added: