Stepfather and mother are dead. Stepfather has raised minor children for 42 years, and the other three brothers and sisters are adults. Stepfather has no children?

According to the law of our country, the stepfather's inheritance should be given to the stepmother (if any) first, and then to the stepfather's children in the legal succession order. If the fourth child is one of the stepfather's legal children, she should have the right to share the stepfather's inheritance, including the resettlement house.

Because the other three brothers and sisters didn't tell Lao Si that his stepfather had died before changing the signature of the resettlement house, this may be regarded as an infringement of Lao Si's inheritance right. Therefore, Old Four has reason to protect his inheritance right through legal means. She can bring a lawsuit to the court, demanding that the inheritance she should inherit be distributed to her according to the inheritance law, and asking the other three brothers and sisters to compensate her for her inheritance rights.

Please note that the specific situation needs to be evaluated according to the stepfather's will and estate status and other relevant legal provisions. If the stepfather has a will, the fourth needs to evaluate the legality of the will and whether it will affect her inheritance right. It is suggested that Lao Si seek legal advice from a professional lawyer and safeguard his rights and interests through legal procedures.

Regarding the resettlement house, if it is really the property owned by the stepfather alone, then the fourth son has the right to share the inheritance. The specific allocation needs to be evaluated according to specific circumstances, such as wills, debts and other factors. It is suggested that Lao Si find a lawyer to deal with this problem, so as to ensure that she can get her due share of the inheritance.