Experiences of introducing a male kitten to an established female cat

[KittCat2]

We have a four year old female cat who is a home body, laid back and enjoys being around people. Though she generally doesn't react well when neighborhood cats pass by - she growls and her tail fluffs up, which suggests she's quite territorial!

Our family would love another pet. We are considering getting a male kitten as feel our established cat would be more likely to accept this (with a long and careful introduction). We are considering getting a Maine Coon.

Does anyone have experience of introducing a male kitten to an established female cat? How did it pan out? I obviously don't want to do anything which would have a lasting impact on our current cat so am keen to hear about other people's experiences please.

We did the usual slow introductions and it was fine, but they've never become friends, they just tolerate each other with the occasional spat, usually in my bedroom when I'm trying to get to sleep as girl cat likes to have sole occupancy of my bed and boy cat sometimes has other ideas.

Both mine are rescue moggies.

Thanks for that @AbacusCat That sounds like a reasonable outcome.