maternity leave not going back

Let me say first I had every intention of going back to work but I have been seriously considering not going back to my job after maternity leave. I can't handle working with little kids while also having a baby. I'm there 10 hours a day (because I have to pump so they're making me have longer hours to make up for my breaks) and I have an hour drive. I just know it's not going to work.....I'm going to be exhausted and crabby and stressed being with kids all day and I don't want that to take away from my daughter......they're only little once. Problem is I took short term disability......now I'm not sure if they will make me pay it back if I don't come back. Does anyone know how to go about figuring this out? I've googled it but I'm unsure. They took a Unum policy out on me when I started working for short term disability, I did not purchase it. It gave me $1,125 over the course of four weeks. I do not want to be stuck paying it back. Is there a certain amount of time I have to return? Or can I just give them my two weeks notice?