yes you can
Not legally. Father can be charged with kidnapping.
Unless you go back to court and have the custody order reversed then yes, you could be charged with kidnapping because while the order is in effect she is acting as the parent.
If she is not the one with custody, yes.
In order for a mother to be charged with kidnapping, there must be a custody order awarding someone else custody, or her parental rights must be terminated. The police would charge her with kidnapping. The father or any other adult could report the crime to the police.
Call the Police. It's Kidnapping. Unless your mother has custody of the child, it is kidnapping and should be reported to the police.
Unless you have the courts and the other parent's consent you will charged with kidnapping and the children will be brought back and you will lose custody and possibly your parental rights.
Since there is no court order and you were never married it is the mother that have custody. He can be charged with kidnapping.
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.
Unless he has a court order that gives him sole custody, yes. She is the one with full custody until he has petitioned the court for it.
If you didn't assist him in coming to your house, it's not kidnapping, but it is considered harboring a run away if he's found at your house.
You will need a lawyer to try and get you full custody of your children and your lawyer will have to prove your husband is abusive to his children. If you presently have duel custody of your children and you take the children to the UK you could be charged with kidnapping.