Flexibility in your job will make a lot of difference. I work from home currently, which means I don't commute every day, and it also gives me the flexibility to be home for my daughter after school and to attend daytime meetings at her school. We bought a horse property, which eats my time in barn chores but means I do get to see the horses every day, and means I live among horsey people. (I doubt we would have done so without the kid.)
I take a pay cut to telecommute and to have this flexibility, but it is worth it to me.
I totally hear you about the loans; I was lucky to graduate in an era where $10,000 was a big student loan and when the interest on student loans was less than a savings account paid.
On the other hand, if kids is something you want to do, you will be potentially pushing the medical envelope if you go past 30. There are not easy choices.
But, finally: you do have choices. When I feel frustrated I think of all the hardworking and bright women who for whatever reason work retail or other jobs with no flexibility and bosses that jerk their hours around for no good reason and who make far less money than I do.
If one of your horses is ready to retire, I would start looking for a good situation there, or maybe a half-lease arrangement. The more financially solid you are when you start this adventure, the better.