The following are correct:
The risk of preeclampsia is twice as high in females under age 18 - females who give birth between 10 and 18 years old are at a much higher risk of preeclampsia
It costs an average of $245,000 to raise a child to the age of 18 - for all income families
Parents who marry before age 18 are twice as likely to divorce as older couples - the statistics are around 50% of couples who marry before 18 will end in divorce especially if they are parents.
These are consistent with the idea that parenting as a teen is more challenging than parenting in later life. The health risks are higher, divorce rates are higher often leading to single parent households which is extra challenging if you are young, the cost of raising a child is high and is a huge burden financially if you are still at school or trying to get your first job or hold down several jobs at once just to afford looking after your kid.