Female Cat Possibly Missing Kittens

[Hellebore1]

My daughter fostered a pregnant cat from the RSPCA several months ago. The kittens were born several months ago and were all rehomed successfully. My daughter decided to adopt the mother and called her Sacha. Sacha was spayed some weeks after she gave birth.
Since then, when the lights are put out at bedtime, Sacha roams the house howling for about an hour before settling down.
Since this only started after the kittens were rehomed I suspect that she is looking for her kittens.
Does anyone have any experience of this?

This is very unusual behaviour for a cat. Usually after the kittens have left a cat gets over it very quickly. I assume you kept the kittens for the recommended 8 to 13 weeks? Although from what I know this is more for the kittens than for the mother.

When I was growing up we had loads of cats (mostly female) and as a result plenty of kittens - for some reason there wasn't the emphasis on neutering like there is today. I don't recall any of my cats reacting in this manner after the kittens were re-homed.

I would say you should take your cat to the vets to rule out any medical issues. I'm not a vet but I would think that if it started after the neutering (about the same time they were re-homed?) then it could be related. I know one of my girls was acting really weird just before we got her neutered and the nurse told me the reason she was acting like that was there was a problem with one of her ovaries and she probably thought she was pregnant.

Oh, how sad. Poor cat!

Thank you both, I will suggest that she is taken to the vet, although she appears fit and healthy generally.
I thought perhaps a small cuddly kitten type toy might work, but I suppose that may actually prolong the problem.