Angie Harmon: Stay-At-Home Moms Work Hard!

Since becoming a mother to three young girls, Angie Harmon has learned how much work it is to be a stay-at-home mom:

"I've always sort of looked at stay-at-home moms and been like, 'Oh gosh, how on earth do you do that? It seems so boring!' There is not a boring moment!," Harmon told PEOPLE on Monday, while hosting the Huggies Big Mover Shoe Auction for the charity KaBOOM. "I'll be in the car for four hours, just from taking them to school and someone forgot a lunch and then we got to go back with the project, it's just amazing to me. I've really been enjoying that."

Harmon, 36, who welcomed her third daughter Emery Hope in December, says that between the 9-month-old and daughters Finley, 5½, and Avery, 4, she and hubby Jason Sehorn have very little time for themselves these days.

"It's funny, we held hands the other day and it was so odd that it wasn't a little hand, that it was a hand bigger than mine," says Harmon. "We're literally just like, 'All right, great game, see you in the showers!' That's kind of it right now – we're outnumbered. They try to take over as much as they can, it's us against them."

The 37-year-old Women's Murder Club actress said her older daughters just love their little sister: "They treat her like she's a doll, so it's a bit alarming at times, but it's really been very easy," says Harmon. "They love her. We didn't have any of the jealousy."