If you're looking for TV shows, Supernatural [it's 15 seasons long so there's not moms in the whole thing] but in later seasons there's Rowena, Jody, and [starting in season 12] an arc about Mary (yeah, she starts out the story being dead, but she gets better :)] I've always really liked how much focus SPN puts on family relationships and it's off the top of my head the only SFF show that features moms in interesting, complex relationships with various other characters and their children who get full character arcs. I mean, there's sort of... x-files too, but I'm not sure how much you'd think that counts...