help - double barrelled surnames

Stacey
So...I have a little girl from a previous relationship who has her fathers surname. She doesn't know this as she has been brought up with my surname and is also known as my surname at school etc (there is also a court order in place to say this will be the case until she is 16) 
I'm due to have my son in 4-5 weeks and my partner obviously wants him to take his name (we aren't married yet). However I would really like my surname to be taken too. I don't want to have 2 children with 2 totally different surnames to me and also want my daughter to have some connection aswel. Iv suggested double-barrelling our sons surname but my partners not keen? What do you all think?