This thinking is way off. So you are saying because someone's parents have educations, jobs and money that one will not have unprotected sex?
On paper she shouldn't be in the situation she's in? What does that even mean?

It's her parents that have the jobs, money and education-not her.
Her and her sister ended up as teen parents because they had unprotected sex as teenagers and they didn't choose abortion or adoption!
(and I don't even know how old her sister is or what age she had her kid)
Yeah, statistically, parents with high levels of education, good jobs, money, etc., are much less likely to have kids who end up as teen parents.
I meant, on paper, if you just took the statistics of her life - her parents were not teen parents themselves (which is a huge marker for it, as teen parenthood perpetuates through generations), they're both well-educated (I think both have graduate-level degrees), they both have good jobs, are upper middle class, she has a close, loving relationship with her father - all of those things, statistically, make it less and less likely someone will end up a teen parent or getting pregnant as a teenager. Her sister I believe got pregnant as a teenager as well; I dunno how old she is currently. So...

makes me wonder what the deal is. Yes, anything can happen, but it's anomalous, especially with both kids.
Having been born to teen parents, having parents of low socio-economic status, having parents who were not highly educated, etc., all substantially up the odds that a kid will end up becoming a teen parent or getting pregnant as a teenager. Common in that situation, rare in the other.
It's interesting - makes me wonder about Chelsea's grandparents and Aubrey and her cousin's outcomes. Aubrey, statistically, is not likely to do anything but perpetuate a bad cycle. Her parents are both uneducated, low income, unmotivated teen parents. Doesn't bode well.
I wonder if Randy and his ex- and current wife were the anomalies or if Chelsea and her sister will be.