I went to school when my oldest was 0-6 years. It was great. Although, school is important you are paying to be there, not being paid to go - your choice and you can pick your schedule. When my daughter was sick, I didn't go ... a call of explanation to my prof and I usually in the good books, fellow students provided notes.
Occassionally, my sitter was unavailable and I often would take my daughter with me. By age 3 she was happy to color quietly during a lecture, and one prof would set her up at his desk and even let her use his highlighters! For those classes she couldn't attend fellow students/friends were often happy to take her for an hour in the student lounge or cafeteria.
I think that going to school is a much more flexible environment for parents with children than most work places.
My child always went to a day-home but I know that most colleges and universities often have subsidized care for lower-income parents.
Probably the most diffcult part of being a student parent is the lack of income.