Problem with new cat intergration

Question
Hi Lisa,

I have a 19-20 year old female who has had the house and yard to herself for all that time.  I rescued a male about 6 months ago ( he is one now ) and have kept them apart because of my old female's nasty attitude about the new male.  Is there some way to bring these two in the open without getting the old female hurt. She weights in at 6 lbs and the male is 12 lbs.  

Jon

Answer
well as long as both are unable to make babies, you can have them in the room together ...but only supervised at first...you will have to be with them at all times in the begining..then as she accepts him and they get to know each other, after about a month id say, you can leave them together all the time.