DD has XP's surname, and will do so until she is 18 and old enough to change it herself. Possibly if she asks I may see about convincing XP to allow her to hyphenate my married name onto it, but at the moment it hasn't come up. DS and I have DH's surname, DD's never really been bothered by different names in the family and will occasionally call DH "dad" as well as calling her father Dad.