You are ramping up the peril with babies involved. We tend to make assumptions about how family names work, but I know it varies around the world. In some your 'surname' is based on a parent's first name and in others it can get a different suffix for women. I never really got the deal with doing double-barrelled names at marriage. That just means you will be writing a longer name for the rest of your life.

!LOLZ