I went back to graduate school when my firstborn daughter was two, working full time and attending school part time. The following year, I gave birth to daughter number 2 in the middle of a term. I took off the week of the birth and was back in class the week after; back at work full time 6 weeks later. The following year, I gave birth to my thesis, graduated with an MA in medieval literature and a 4.0, and skipped my graduation to give a paper based on my thesis findings at the international conference in my field. I'm still working full time, and have now applied to doctoral programs.
All of this is a DECADE after my first master's attempt, with no kids, back in 2000.
I think as long as you are doing the program you want to do and are happy, your family will also be content. This has been the case for me. YES, it's hard as heck, especially in terms of time (I'm in literature, after all!) There's never enough time to go around. BUT, in the end, if you're happy you can always make things work out - have you ever noticed how that goes?
I'm very worried about money - in other words, no fellowship/assistantship, no PhD work - it's that simple for us. But if I get in somewhere and am funded, we are going to go for broke. Because it's better for my family - especially with two daughters - to have me reaching for my goals and fighting for my dreams than to have me bitter and disillusioned and harping on how unfair things are for women with kids. I never want for a second to be able to look at my kids and think "if it weren't for you I would have..." - so I don't. I just press forward and chase down my dream, and they are very happy, bright, funny and well-adjusted girls, so I guess we're not screwing up too badly, yet (of course, they're only 5 and 3...! lol)
My philosophy on having a family and going for the PhD is: there will NEVER be a good time to have kids, not if you are a woman. If you want them, you just need to go ahead and have them. (preferably not at the very beginning of the program, and not during your thesis/dissertation defense, or orals, lol). But really - you can wait until post-tenure (good luck with that) or wait until you have your degree - but in the end, when is it really going to be convenient to have the family?
I refuse to compromise my dreams. I wanted a family - I have a family. I wanted the MA - I have the MA. God willing and up to the funny bunch of squirrels in the admissions offices, I'll get the PhD as well.
I'm very lucky, in that my husband is extremely supportive of me. But don't fool yourself - he's not bending over backwards to accomodate my schedule, it's vice-versa most of the time, with me doing the majority of childcare/chauffeuring duties, etc. etc. He takes them out on Saturdays and I read like a maniac and grade papers. It works - but it only works because I want it badly enough to make it work and I'm willing to compromise on sleep and have no social life. That's OK. I have the MA, and I'll hopefully get a PhD, and then I can research and teach and write books for the rest of my life. Getting paid to read books and talk about them.....ah, heaven. Hugs and kisses and singing my girls to sleep, and baking brownies....ah, heaven. Hugs and laughing with my husband....ah, heaven. Put them together and for me - that's the greatest life I can live.