If your husband dies will his young child who he has full custody of be sent back to his mother or be allowed to stay with you the stepmother?
Having full legal or physical custody. If it is full legal
custody the mother has given up any legal claim to the child. If it
is full physical custody with joint legal custody the child will be
in the legal custody parents home. She may elect to give the child
up to be adopted by the stepmother.
In many states (and maybe in all states) if the custodial parent
dies, then the non-custodial parent gains custody, provided that
that his/her parental rights have not been terminated (and just
because he/she did not have legal custody does not mean that
his/her parental rights were terminated). Of course, in that event
the stepparent can still petition the court for custody. Check with
a local attorney.