What should you do with my daughters and son if my wife dies?

Hey my name is Aaron and I'm 21. This is my sister's account. I am married and have three babies: Lauren born 12/21/08, Lydia born 7/16/10, and Liam born 7/16/10. My wife Katherine is 17 and a senior in high school. We were both raised as Christians and still are, but we did some things that were against that. When I was 19 and a month before she turned 15, we had . The day after her 15th birthday, she found out she was pregnant. Then in December she had Lauren. We got married in June 2009 when she was 16, Lauren was 6 months, and I was 20. We moved into the two bedrooms in her parents' basement because it was the best for us and Lauren. Then in October, she got pregnant with the twins. And in July they were born. We are raising the babies as Christians and going to make sure they don't make the mistakes we made. We still live in her parents basement. We will move out whenever we can afford it and once we're both done with college. Anyway, today Katherine and I were watching TV, and all of a sudden she started complaining of a headache. About a half hour later, I walked in our bedroom and she was laying on the floor. I listened for a pulse and there was one. I screamed for her mom and she came down. Her mom drove her to the hospital. They don't know what happened but Katherine hasn't moved at all. They are doing tests. Right now I'm at home because it's Katherine's dad's turn at the hospital. I came home to take care of the babies. I am petrified that it's something serious. If she dies what would I do with the babies? Should I stay here and let her parents help? What would I tell Lauren because she's a major mommy's girl? PLEASE Help. I know I sound stupid but I am petrified of losing my wife. Do you have any idea what could be wrong? What should I do if she does die?