Go have the interview and mention your family plan

as you are thinking. If they think you (with your circumstances) are the best choice, they'll figure out ways to accommodate. Many young women working in management positions are required to travel, look at the ones at Big4s, investment banks etc, very high stress jobs, yet a lot of them have successfully managed to have both. If you are highly valuable to the money-making cause, you have a lot of say in how you want to do certain things.

If you are a dispensable entry-level resource who can be replaced easily, of course nobody would bother.