Is my kitten in heat?

I have a female kitten, Jazz, around 5 or 6 months of age, who started making loud continuous lovey, slurpy, purry sounds just today. She's being pretty friendly towards my male cat, Bo (neutered) although that's really nothing unusual. But these sounds are. I know that cats can have kittens as early as 6 months of age - are these loving sounds an indication that Jazz is in heat? Or is she just developing her personality and conversational skills? Bo chirrups and trills all the time so maybe she's just picking up the language from him? I hope so because it's a sweet sound and she's been pretty non-vocal since I found her as a stray 6 weeks ago although she's always been an "easy purr." She is NOT being loud or howling which is a common sign of estrus.

Jazz has an appointment to be spayed in about 3 weeks. Would being in heat affect her behavior in any other ways?

From one cat breeder's site:


Different queens will exhibit different signs of being in heat or estrus. Unlike dogs, cats rarely show signs of vaginal bleeding during estrus.
However, their behavior changes greatly, with the majority of queens becoming quite vocal and loud, and showing increased signs of affection.
They may roll around on the floor or plop down right in front of you as you are walking; they constantly want to be with you and be stroked, and
when you pet them on their back, they will raise their rear end up high and knead with their front paws.

So ... maybe! I'd be EXTREMELY careful about keeping her indoors right now. My brother's small son let "Midnight" out cause she was meowing a lot - the subsequent kittens all found homes, THEN Midnight got fixed.

Sounds like my little girl is becoming a woman right before my eyes. She has been rolling on floor, belly up, today which is another new action on her part. She is an indoor only cat - so there's no chance of promiscuity and pregnancy. How long does the heat cycle last?

Sounds to me your cats in heat. You should have her spayed right away.

http://www.feline-behavior.com/html/estrus.html