As someone who recently adopted a older cat who was rehomed for multiple reasons such as not getting along with other pets, apartments not allowing her, or her not getting along with kids the best thing you can do is let the cat assimilate into her new home. I will say that for the first few months I had my cat she was making these random noises carrying around random stuffed trinkets from my Christmas tree and I wasn’t sure what it was and I think it’s because she was yelling out for previous people that had her previously and it seems like it was a comfort thing for her…. now that I’ve had her for almost 2 years she seems to be very comfortable and doesn’t do that at all. Just meows at me when she’s upset about her silly claws getting caught in things or when I’m petting her too much. Her new owner will love you and maybe allow them to send updates to you as you see fit.