I have a 3yo daughter and a 1yo son, so I know how difficult it can be to juggle family and study time. (Especially since my husband is out of town most weeks.) I think being organized can go a long way in helping you to get the most out of your time with your child, while still being able to succeed in school.
I bought a cheap dayplanner (just a basic calendar inside), and at the beginning of each term, I go through the syllabus for each class and write every paper, project, quiz, test, etc. in it so that I always know what needs to be done, and what priority to give each one. That way, if I have 3 projects due in one week, I'm not left scrambling during the week before trying to get them all done! It's amazing to me that no one else in my class does this, yet they're always asking me when things are due.
Other than that, it just depends on what kind of routine you have with your daughter. You may find that it's easier to just wait until she goes to bed to study. Hope that helps!