Advice for rehoming a dog please!

Hello. I am rehoming my pitbull to the nicest girl ever. it's been about a month and we've had a play date at her house every week. We meet up at the park with my dog and her dogs and they are completely fine, even outside her house they get along but once we get inside her house Sokka (my dog) just barks and barks at the other dogs. We are making progress because the first time they wouldn't stop barking at each other but now they fall asleep in her living room but after a while my dog will being barking in her house again. Each time we visit there is progress and a step further but does anyone have advice to make this process faster? Please and thank you.8