I don't think of it as giving my kids "less of me" or less time -- I think of it as if I'm taking care of myself, they get a "better quality of mommy time" when we do things together -- it's not the "quantity, it's the quality" and I know from my experience that I was miserable and my time with the kids showed it when I was eating bad and not exercising. Now we have more fun, I play the games they do (with the energy I need ) and I'm a happier person.
I love the poem as well. It's a tough one for me. But, I have also learned that incorporating my children into my fitness goals works very well for me as well. Staying on plan also makes me happier, better balanced, and more available to them as something more than a snappy old hag, which I tend to be when I feel like my life is spiraling out of control.
It sometimes feels like we have to give less of ourselves to others in this process of getting healthy, but in the end it really is about giving them MORE, isn't it? We can be better friends, wives, mothers, teachers or whatever other jobs we have, and everything else when we get healthier and happier.
Taking some time for yourself is NOT selfish and inconsiderate. It's the very best thing that you can do for your kids and your family. They NEED and will benefit greatly from you being healthier, fitter, more active and HAPPIER.