Me and my son have different last names. I think it breaks my heart so that my daughter may have my name.
I knew a couple who changed their names to her family's last name when they got married. (He did not have a good relationship with his family at all, and liked her family fine.) It was not a problem.
If you are going to give your son your last name, do it when he is born, rather than having to go through the extra step of changing it. You'll have to do that for your daughter, why add to the load.
I have a different last name from my son (because I never changed my name when I got married) and for family reasons my son got his dad's last name. Sometimes people in my son's grade school think I'm my son's stepmom, which irritates me because I carried him! lol
Relatives of ours changed the whole family's last name to something new.. That worked out fine, and they had the fun of picking a last name that was about halfway between both of their original last names, and was cute and distinguished too.
My daughter carried mines and her father last name. She has two last name because I couldn't choose what last name I wanted her to have. The only thing is that when she gets married she would drop my last name and carry her dads last name and her husband. But at least for now she mines and his. So u can consider using both my it will just have a dash in between. Like for instance. Pierre-Sanchez is my daughters