I think this varies from one individual to the next.
Some people realize that it is difficult to balance work and family. I am lucky to have family members in the region, and my parents pick up the slack. My husband, who also works at the House of Commons, has flexibility that I don't have with my MP. Our schedule is actually planned out weeks in advance in terms of who is picking up the children and at what time, who is booking appointments, and so on.
It really depends on the person. I think it is possible to raise a young family while working in Parliament. We can be parliamentary assistants, MPs or legislative assistants on the Hill, but that requires a great deal of organization.