My niece wants to get emancipated, she'll turn 18 in 6 months, I don't know what to do

Tell her that by the time she gets to court she will already be 18.

First does she have a job to pay all of her own bills, can she afford to rent her own place and live on her own? If not, then she has to do that first.
After she has a job and enough money, she would hire an attorney to file to be emancipated,

Plus of course she has to have a reason, why she needs to leave home, abuse, fear, or some treatment issue