Name every bug, bird, dinosaur and tiger as female. The world does the opposite so we have to push.
"Hello caterpillar, where do you think she's going?"
"That's a scary T-Rex, do you think she's going to eat the other one?"
"Cool shark, she has a LOT of teeth"
And then watch other people be confused and ask how you know it's a female. My reply, "how do you know it's not?" And try when anyone including DD calls something male, to be curious. Why do you think the rhino is a boy? The whole world names animals, particularly big, exciting ones, male. I do the opposite.
I even changed the sex of characters in books because so many are male. And didn't allow any TV or films where default was male and 'female' was a character type. See: Paw Patrol, Smurfs, anything that doesn't pass the Bechdel Test. I didn't encourage things like My Little Pony (a secret feminist medium) and anything by Studio Ghilbli. The girls are all great in those.
And have as many women in different fields you can name without thinking about it as possible. So you can field any questions/comments, particularly by mean boys. DD came home really upset one day because some boy told her girls couldn't be spies. I knew Noor Inayat Khan off the top of my head. Same with war. I knew the inventor of Kevlar was female. And about the Night Witches. Also science and ninjas and anything children find cool. Name them without blinking. DD is lucky she has some pretty amazing women in her family. Talk about the fantastic women in your family tree.
And buy Dear Ijeawele, or A Feminist Manifesto in Fifteen Suggestions by Chimamanda Ngozi Adichie all about raising a girl.