Silly question I suppose but how do you know?
I took a cat that my friend needed rehoming and I am just a bit worried that she's unhappy.
She is quick to purr and loves sleeping on my bed, day and night. However, I do have two quite energetic youngsters (DD is 4 and cat mad and DS will be 2 just after Xmas and is very excitable), so when she ventures into the more communal parts of the house, she gets a lot of 'attention' and then kids do their usual running, screaming, 'being kids' things - not at her, just in general! She does play (ish) in that she likes batting a little ball but doesn't play with the few toys we've bought her and she has a tendency to bite if she gets overwhelmed/overexcited??
Because she's been rehomed, I was advised to keep her in for two weeks but am worried that when I let her out (mid next week), she won't come back 
As mentioned, she curls up on my bed and stays there pretty much full time at the mo and comes in for some nice snuggles when I go to bed (and does come down to see me once the kids are in bed). What do you think?