Rose, you ask a very good question. The fun thing about civil engineering is that there is a place for everyone!!! Given your inquiry as to family, you might not want to consider a job in construction which would require a significant time away from home to be at the job site. However, as a designer, there are several firms who are looking to employ women and who have flexible work packages that would potentially allow you to work either a reduced work week, and/or do some of your work from home. I had an employee who wanted to raise a family and still wanted to work, but recognized that she would not be up for promotion if she was not working at the firm full time. Understanding her personal desires and trying to blend them with our company requirements, we worked out a package that allowed her to work a 32-hour work week, thus allowing her to still maintain her benefits, and allowed her to work one day of this time at home. She has been with the company since this very day and 20 years later, she had completely raised her family and came back to the firm full time. 3 years ago she was made a Vice President. Thus-anything is possible when employers recognize the value you can bring to them.
There is also an option to work with a government entity that typically has either reduced hours available, or at least set hours at a 40-hour work week. This may also allow you the comfort of knowing that you can indeed set the right amount of time aside for your family.
There are no right or wrong answers to this question. The solution comes down to the individual and the individual situation. You should discuss your personal and career goals with your potential employers. Together, you can design a work environment that works for everyone. Good luck with your future!! Civil Engineering is a career that helps people and our world could not exist without it. I applaud you on your efforts and desires to pursue civil engineering.