What are the signs that a cat is coming into heat?

I know I should know this , but I've not had an unspayed female for a *very* long time - if ever (can't remember if we spayed a our first girl or if she'd already been done...well, I was 3 at the time )

Asha is going to be spayed, but isn't fit enough yet. She's around 9 months old. Last night she wouldn't settle - she was twitchy and edgy, but wouldn't focus on play like she has been. It's like she suddenly has ADD or something. There's a lot more kneading and meowing at me (and she's vocal anyway!) , and just doesn't seem quite herself. Does this sound like a cat coming into heat?

Sounds like it; certainly nine months is old enough.
Another tell-tail [sic] sign is: does she stick her butt into the air.? Is she even more cuddly, needy than usual.
If nothing else has changed, then, yeah, she might be going into heat--with the caveat that any change of behavior can be a sign of illness.
FYI, I was co-fostering a cat who cycled in and out of heat about every week (or so it seemed). She lost a lot of weight and developed some skin allergies before we could finally get her spayed. You might want to call your vet and tell him/her about Asha's changed behavior. Good luck!

Thank you It's a little hard to tell about cuddly/needy because she's very much that sort of cat anyway :rub:

Not a lot of butt in the air, but definitely more grooming of her personal regions and rolling around more than usual (I say more than usual - this is her 3rd week with me so it's a little hard to be sure of her 'normal' yet.

I hope to be speaking to the vet about some of Asha's test results today. I'll definitely bring this issue to her attention at the same time.