You probably don't want any of the "state streets" in College Station. When I was in school (with small children also), I lived in the Oaks area in Bryan. I have also lived in the Southwood Valley area of College Station and I currently live near the hospital and Blinn College in Bryan. I still have one child at home. All three areas are family friendly and on/near a bus route to the university.
Bryan is a little more affordable than College Station, but I agree with Aggie98 - anything under about $700-800/month can be kind of sketchy.