FWIW I made the dumb decision in high school and ended up with two sons out of my first marriage. I was 18 when my first son was born, and 19 when my second was born.
My life hasn't been easy - but I wouldn't trade anything because the experiences I've had taught me a bunch. In the end, what this means is that your daughter will have to forget about the 'fun' part of being a young adult and grow up faster than she wants (or needs to).
As long as she has love and support I'm sure she will do just fine. That has been my secret... a family that didn't exactly cheer, but who made the best of the situation.
If you need advice from the perspective of someone who put themselves in the same situation let me know.
"You can't reason someone out of a position they didn't reason themselves into."