I think you are safe for awhile... like the others said, the first heat usually starts somewhere around 6 months (but I have heard of 4 months too!). And get her spayed as soon as you can or you are up for the same headaches I'm having right now... my little girl has been in heat since Tuesday evening and its HORRIBLE! (I've heard the spring heats are usually the worst... and she is proving it!) I had to keep her locked in my bedroom most of the time so my 8 month old wouldn't decide to be man (he goes into the vet in an hour!). As soon as I did the switch this morning (I put Oliver, my male, in the bedroom, so Serena can have some "house time") she started HOWLING like crazy! This was at 5A.M.! My other male, who is fixed, is going crazy because Serena is following him around and won't leave him alone! He tries to do what he's suppose to, probably just to shut her up for awhile, but he doesnt realize that just laying on her doesnt the trick, but him just laying on her calms her for awhile. Thank goodness for neutered males! LOL But as soon as this heat passes, she is off to get the zipper!