K.L.
Goodness, it's nice to find someone in my area! Everyone seems to be scattered so far from me. I am from Duncanville as well.
Anyhow, you could always try the pumpkin patch in downtown historic Cedar Hill. It would at least be a nice place to get some cute pictures taken. I have heard a lot of great things about Boo at the Dallas Zoo. I have never been but was also considering taking my 18 month old there this year.