it is my understanding that at the age of 13 they can decide what parent they want to live with.
Children "can decide what . . . they
want" at any age. At the age of 8, a child can "decide [that he] wants" to live at Disneyland. At the age of 10, a child can "decide [that she] wants" a pony. However, as is the case with adults, children often don't get what they want.
Where a child lives is determined by his/her parents and/or the courts. Starting around the age of 12-13 (depending on the child's demonstrated maturity level), courts will give some consideration to what the child wants when making a determination regarding physical custody. However, the child does not get the final say until he/she reaches the age of majority (21 in Mississippi).
I do not agree with her dating going out with friends having sleep overs body piercings.
Any piercing isn't legally possible without parental consent, and you could probably get the court to order that neither parent may consent to any piercing without the other parent's consent. You
might get an order prohibiting unsupervised dating, but I can't conceive that any court would enter an order that prohibits a child from going out with friends or having sleepovers.
She now has her no pierced which is illegal in Ms anyway.
No it isn't.
Which child? I was about to write that a 13-year old could only get pregnant as a result of forcible or statutory rape. However, leave it to Mississippi to have
a law that makes sex with a 13-year old legal (albeit only if the other party is less than 24 months older).
My 13 year old informed me that his dad allowed her to have a boyfriend. Allowed for him to have sex with her and now he has" enrolled her in home school" which basically means allowed her to be a 9th grade drop out. Can this be neglect? This is not in my daughters best interest
Home schooling is common and legal, and there's nothing wrong with young teens having boyfriends/girlfriends. I have to question what "[a]llowed for him to have sex with her" means exactly, and the answer to that obviously influences the answer to your question about neglect.
In any event, and while you didn't tell us what your divorce decree or custody order says about who has physical custody, you are obviously free to seek to enforce or modify the decree/order, and I suggest that you consult with a local attorney about this.