Joined: Aug 2008
Posts: 1306
vital statistics
4/4/2016 at 1:02 PM
Have you looked there for information? It seems to me that she would need your consent unless she has sole custody of the child. I don't think she'd get very far in taking it to court - it is not a thing you can make someone else do.
If she has a reason, such as other children with the new husband and she wants him to have part of the new husband's last name so he feels included, I can see that. You may consider it if you think it will benefit him in some way, but otherwise you could counter that he can hyphenate with HER maiden name and she can choose to do the same with other kids.
ex/
Child's current name = Joe Smith
Her married name = Jones
Her maiden name = Brown
If she wants half-siblings to share a name then she could change his name to Joe Smith-Brown and any future siblings could be Jane Jones-Brown, Bill Jones-Brown, etc.
I get not wanting your child to carry another man's name, and leaving the decision to him when he is older.