Elizabeth,
Interesting thread. I suppose they will just have to pose for you. Then you can draw and have your quality time with them. Of course I have 2 daughters, one who is 21 now, the other 12. So I know, once they get to that age, getting them to pose is like asking them to have a tooth pulled with no anesthesia.
I suppose there is a difference between men and women in this regard, that men tend to put work before other things more easily. But this is changing every day (especially since 9-11). More and more men are wanting to spend more time with family than in the past. I look at my art as my job and I regulate my time in the studio and time with family accordingly.
This is an issue that not only artists must deal with. Today more and more people have home offices and must deal with separating family time from work time. It is very easy to let one or the other suffer. Because the office (or studio in our case) is right there in the home you can work at any time so it is easy to get so caught up in it that you work all the time. Especially when you really enjoy your work as most artists do.
On the other side is the problem that family interruptions can distract from work time. Family members feel that you are home so just as when they are home you are free to answer their needs.
My solution to both of these is I made a deal with my family. If they leave me be from 8:00 AM to 3:30 PM I will not work from 3:30 PM until after dinner.
If I have a meeting in the late afternoon then I make up the time with them on another day. This is not that I do not work in my studio any other time but I allow interruptions outside of my designated work time. This also keeps me on a schedule.
This works for me and my family and respects my work time. Most of the time, that is.
My daughters try and take advantage (knowing I will not be paying full attention to them when I am working) to ask me for something I would normally say no to. This can be a problem when my wife comes home and asks me where the girls are and I do not know. I find out later that I gave them my credit card and said it was OK for them to take my car to the mall.
Now if you are not a full time painter then you would of course need to adjust the time around your other full or part time job to still give you your time to paint. By designating work time as a time that you are not to be disturbed and family time during which you WILL spend time with the kids or your spouse and you live up to your end of the deal then your family should respect your wish to not be disturbed when you are working.