I'm a newbie and hoping you lovely cat lovers might be able to share your experience with me.
After 9 months of losing our dearly beloved Louis we decided to move on gradually and adopt a rescue cat. Prior to this we had two sibling cats, Louis being the last to die

We looked at quite a few cats and interacted with them, but felt sure with Sadie that she was right for us. (Household 2 adults, & 2 occasional kid adults) she was very affectionate and wasn't timid each time we met her. Also, she is very gentle and never gets her claws out.
Finally when we got her home she was the same loving puss we fell in love with at the rescue centre. She began to settle in nicely with no real issues at all.
However, after a couple of weeks she began to be very standoffish, would not come to sit on our laps, nor rub against anything in the home, which I found very odd. It is almost like she is waiting to move on again, not bonding with any of us and not marking her scent anywhere. To me, she appears to be grumpy and depressed. I then used Felliway which really didnt make any difference to her moods.
She is only showing communication with us now when she is hungry. I feel like we are not the right family for her and it is making me very sad seeing her like this. Should I think about rehoming her. Breaks my heart to hear me say this, but she is so unresponsive.
How long do you think this should go on for, considering we have had her for 5 months now.
Any advice will really be appreciated.
Thank you in advance.