I agree with most of the others. If the child(ren) are normal over 5ers sure no problem.
Under 5? absolutely no way not ever.
I can remember going downstairs on Saturday mornings to watch tv as young as 5 while my mom slept. I never got into trouble, I just watched my shows until she came downstairs. And even though I can't remember it, I know it went on well before that because my mom was a single mom by the time I was 15 months old (and I'm still alive tee hee!) My DH works long hours many days, especially during fall and winter, and there are many times I have to shower while the kids are up. I usually let them watch a video or put up the gate and let them play in their room until I'm done. They're way too young to be alone while I sleep, though. (Paddy is 3 and Henri is 2)