I think that anyone who is a work-at-home mother must run into this issue - how do you manage your work time while at home and also taking care of your children?
Do you schedule a strict regimen and then stick to it no matter what? Hmmm. Well, if you're a mother you might have tried this and found out that's it's not quite possible while also handling the various interesting adventures that come up with children. OK, I'll just go ahead and say it - uh uh, it's not going to happen. :)
You know, I don't know that there is an exact answer to this. Sometimes I spend all of the day with my little one, especially when it feels like he needs the attention. There are other days when he's completely enraptured with his own thing, playing with his toys, etc. then work in more time.
OK, I thought of some good advice - don't expect to have a very strongly structured day (e.g., 10:00 - make phone calls, 11:00 prepare next campaign, etc.). Make a "to-do" list of things to get done in the next day or two, then do them when it's easily done. (My best times are naptime, after bedtime, when he's playing with his toys.)
My child is my priority. I've also got to get food on the table, and am fully responsible for that as a single mom. But I've found out that I can work from home (strictly), be a successful businesswoman and a successful mother with a healthy, happy child. I'm doing it.
PS: Mom's - I also find that if I take my child to the park, go outside for a walk for an hour or two, the whole day seems to go much better for me and my little one.
PS - 2: Don't forget to give yourself a pat on the back now and then. :)