I'll be 34 in March, and I have a 20 month old child and a husband, and I will be a 1L this fall. I say go for it! We prepared by paying off all our debts because my husband will stay at home with the baby while I am in school, though he may give baton lessons for a little side income. I will be working during the summers as well. I am waiting to hear back from the schools to which I applied, but I do have an offer of a full ride from a Tier 3 school.
There is nothing you can do about your undergrad GPA at this point, but do not underestimate the LSAT. I studied using a single practice guide and doing a couple of tests. At the time, I thought that would be adequate, but in hindsight (after reading a lot of these boards), I should have done much more. Start studying now!