You have had life easy with your cats Mary until now and have to remind you that its taken Sasa 7 years to allow stroking but only on her bterms at top of stairs and she vwaits their every night bfor her strokes.
However that is it, no other contact and she still runs away most times if I try to walk past her.
So much depends on their past lives and they never forget.
I think you are right she has been with you a very short time and Kocka used to love sleeping in a drawer full of socks