LOL LF yep I made that joke too - did not go down well either - men
When you get married you can choose to use your married name or maiden name. Birth certificates aren't changed anymore so if you want to keep your maiden name no dramas and if you want to change then just present your wedding cert - very simple. Same with changing back - when me and ex seperated I just asked the bank, ird, etc to change back and since they already had my birth cert it wasn't a problem.
You can change your childs name by deed-poll but if the fathers name is on the birth cert then you need his permission - of course if its not you have all the power

Just been through this so yeah Chickaboo is right with the pricing.
Tania I guess it really depends on your daughter about the name. Shes still quite young so thats why I thought changing her name (or even hyphenating it) might be easier coz of course if she was 13 she'd probably have a very definite opinion but she may actually have a good idea of what she wants right now! I also thought that as there doesn't appear to have been any other father figure in her life she may really identify with your DP as her dad. Hope you guys find what works for you