As a mother of nine, Rachel Campos-Duffy has certainly had practice at pulling off Mother’s Day without a hitch. And she’ll certainly be front and center when the family celebrates today with a brunch at a friend’s house — although not until she’s finished her shift co-hosting “Fox and Friends.” “It’s the same for all moms. The kids will make me cards and give me flowers. We’ll go out to brunch, but try to do too much work,” she told The Post in an interview. Life in her and husband