I used to know someone who had three grown up sons and one grown up daughter - she was fairly close to all of them, and they all went on holiday with her at one point or another.
My son is (at the moment - he's 11) very close to me, but that may just be his personality - he has ASD and doesn't really get the whole 'blokey' thing and is still in many ways a little boy.
My daughter is almost 14 and at the moment fairly brittle.
I find parenting both of them draining in some ways and very rewarding in others. When they are small it can be easier to think in terms of boy stuff/girl stuff that you're most comfortable with, but as they get older they become very much their own people, and that may well include not fitting into gender stereotypes.
Your son is still very young, unless there are time pressures do you need to try for another baby now? Maybe work through some of your feelings - do you want to have a girl because that's how you'd imagined motherhood (which is fine)? If you had another boy, would you be really disappointed, or would the newborn phase win you over?
I wanted to have a girl - I had a sister, she had two daughters, I used to think I wouldn't know how to 'cope' with a boy. Then I had a daughter, and I assumed I would have another one, but I had my son. Who was gorgeous and snuggly and his own little person. Who could pee on my shoulder at nappy changes in a way my daughter didn't but in the early years that was the only difference. Who went through Thomas and Lego phases - but so had his sister. And who now witters at me about Pokémon whilst his sister witters at me about teenage social media stuff. They're both lovely.