This is just my two cents but.. it's just a name, really.
My mother didn't change her name when she married my dad, so I have always lived with this idea that it doesn't matter all that much, hence my opinion.
But think about it. Does it matter if you all have different names? Like, does it actually MATTER? Does it change anything? Does it change the way you feel about D7 or vice versa? Not at all. Besides, in the long term she may get married and change her own name..
I feel like I didn't articulate this very well, but I don't think you should worry too much about whether you, D7 & any future child/ren have the same name.
However, I can see why you might think strongly about changing your own name back to your maiden name.
