After reading your story I thought about the line, "What I didn't know then, and wish I didn't know now...", quite a bit and I'm certain it's true for many. It's evident your character had to grow up extremely quickly. Your interpretation of the prompt is a good one and you've touched on some of the most devastating secrets family members can keep from each other.
You definitely have potential to expand on this piece - especially with respect to the characters. As a reader I'd like to know a bit more about them and how they cope with keeping such dark secrets. Even though your story deals with a big family, I think you've already pointed out some key people who play an important role in your main character's life. I like the first person point of view.
I have a few comments and observations for your consideration; please remember these are my suggestions for you to use or discard as you see fit.
My family always had their fair share of problems. Five boys and four girls growing up in a small house with an abusive father. The boys were wild, and three of the four girls got pregnant while still in high school.
You've revealed a lot within these three sentences and I think with a bit of editing you can make it more hard hitting and tighten up your writing so it flows more freely. Here's my suggestion for editing My family always had their fair share of problems - five boys and four girls growing up in a small house with an abusive father. The boys were wild and three of the girls fell pregnant while in high school.
There are the stories where all of them share one bathroom, or how there were only three beds for the entire family, and most of all the stories of how their parents always forgot about their birthdays.
Again, I would suggest a bit of editing. There are stories of them sharing a bathroom and only three beds between the entire family. And there are the stories of their parents always forgetting about their birthdays.
and found out that she stole around thirty thousand dollars
I've read over this sentence a few times now and it feels like there is a tense change towards the end. I'd suggest changing it to "she had stolen around thirty thousand dollars".
accusing things back obnoxiously
Perhaps "throwing accusations back obnoxiously" would work better here.
Everyone tried for months, they wrote letters, sent her a birthday card, still, but she never responded.
I've noticed quite a few unnecessary commas throughout this piece and I would suggest going over it to eliminate some of them. Here for instance, you might consider splitting this sentence into two and revising the use of the word "still". "But" could also be replaced with "and" Everyone tried for months. They wrote letters, sent her a birthday card and still she never responded.
He cost himself the own loss of his family, because his wife left him and immediately took him to court.
In this sentence the word "cost" suggests that he had to give something up or lost something, therefore I would change it to "He cost himself his family, because..."
Around this time in my life, where all these stories were wrapping together
"where" should be "when"
living at mother's parent's house
"parent's" should be "parents", unless the mother only had one parent.
told be never to tell anyone
"be" should be "me".
I admitted back to my mother
The word "back" is unnecessary.
two months later never saying another
A comma or hyphen after "later" would create a pause for effect.
Overall, this is a good, emotional piece.
Good luck in the contest!
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