Smokie's not cleaning the babies' butts...

Well, I have noticed, they are peeing and pooping, but she hasn't been cleaning their butts. Should I worry about this, all are fine as of now, but Smokie isn't doing this.. They are peeing, and pooping fine, but Smokie isn't doing her job! Although she is feeding them. And I haven't seen Smokie come out of that closet once to do her job... Should I worry about all this, or do you think she is just fine? Because she hasn't been to the litterbox that I have seen, but I do close the door right before I go to bed, and it's open when I wake up. So maybe she knows my mom will have a cow if she is out when she is here. I am a bit worried though.. Thank you for reading!!