Just like anyone else who isn't the biological parent she would have to go through the courts and prove she is able to take care of the child better then anyone else and since she isn't really related she will have to prove that there is a strong bond between her and the child
no no
If paternity has not been established, then you would have to do that first. Once paternity is established, then you have to right to petition for custody.
Eminem has custody of his daughter and also his niece- his ex-wife's sister's daughter.
no, My daughter had a baby at fifteen and I Had custody until she turned 18.
no
No. His wife Priya Narang had Primary custody of their daughter.
Through some kind of family inclusion of the girlfriend, the mother of the boy can gain custody. An option could be adoption.
yes he should do
not without your parents permission, but if they do, they should lose custody rights.
file for custody
see related question
For 1) are you in custody of your daughter? If you are in full custody you could take her to court for kidnapping is your EX mother in law in custody of your daughter? Do you have joint custody? If your ex mother in law has no custody over your daughter you could take her to court, she is not authorized to take care of your child.