That site has a listing of all the programs offered by DHS and locations of DHS offices in oklahoma county. You can even get applications for some services online. They can help with medical for your daughter and even with trying to collect child support from the 18 year old living in Colorado. I don't know where you are located but they do have an office right near 50th and May...my suggestion avoid the 23rd office if you can.
WIC is through the health department, they have a really nice office in edmond and allot of other resources for young parents.
There are several alternative schools in OKC www.okcps.org
I don't know which ones are geared toward teens with children but you can get the contact info from there.
Good luck with everything, I know this must be a sad but joyful time right now. My sister got pregnant when she was only thirteen and my mother became a mother again for awhile...we all pitched in as a family to help her out. My sister had a very hard time giving up her friends and social life. Its so hard being a young mother but a good support system can really help.