Suggest you do any research you may need to do regarding teen pregnancy, pregnancy, having a baby etc...
Then work on 'more things go around it' in regards who/what/when/where/why.
That's journalism there, the '5 W's,' supposed to be answered in the first sentence or two of a news story. Yet they are also good questions to think about for any kind of writing, regarding each character, place and deed.
As for names, http://www.babynamer.com gives lots of names and their meanings... thousands. For last names, and sometimes whole names, I open a big old phone book and mix and match.