This has to be done through the courts.
see link below
In fact you can, if the sim you want to gain custody is related to the person who has lost the child they may gain custody of the child and will move in with them. I'm not sure if it automatic or if it is ocassional but you can definetly get custody.
Yes
If no custody orders exist, a motion for temporary custody can be made while in possession of the child. An emergency motion for custody can be filed with evidence of immediate danger to the child.
You file an emergency child in need of care and custody in court. See link to learn how.
By capturing the child. Face it, they won't stay captured for long.
yes
Depends on circumstances. A single mother has a presumption of sole custody at the time of the birth of the child. Where married parents are separated, there is a presumption of joint physical custody whether or not support is ordered.
The sister must make an appeal to the courts to gain custody of her brother. The judge will weigh the reasons each guardian believes she should have custody of the child and then make a decision in the best interest of the child.
Child In Need of Care Motion
A child does not need to be abandoned by their mother for a father to be awarded full custody. If the father can demonstrate before a judge that the mother is unfit to parent, the judge can award him full custody of the child.
You have to prove your case and convince the court.
No