will they ever get along??

I posted back in January about a feral/stray we took in before a big snow storm, and she has been living in a bedroom for a little over 3 months.  We have an existing cat who is same age (3) as feral and is very interested in her still, though we kept them apart for a good 5 weeks.  Now we have open door policy for the bulk of the day except for mealtimes and night time.  Feral girl will hide under the bed/couch whenever my other cat comes to visit.  When Other Cat sees Feral Girl running under the bed she will sometimes chase her, and Feral Girl will still growl at her.  No major injuries besides a tiny scratch on the nose for each over the past 3 months.  the rest of the open-door visits are invariably Other Cat sitting on the scratching post perch, or sleeping on the bed, while Feral Girl waits her out under the bed. Feral Girl will not leave the bedroom, and has not ever, for fear of running into Other Cat.

With us, Feral Girl has become incredibly affectionate, will sit on my lap, and I can touch her pretty much anywhere with little/no reaction, though if we move suddenly or make an unfamiliar sound she's off like a shot.  I understand she may always be this reactive from living outside in NYC.

Anyhoo - anyone have stories of cats developing at least a tolerance for each other after 3 months? Or should I be looking for a single-cat home for Feral Girl so she can relax and have the run of someone's home?

After you kept them apart for 5 weeks did you do cat to cat introductions?  Here is a link http://www.thecatsite.com/a/introducing-cats-to-cats

I have a similar problem and I can totally emphasize.  I brought a stray turned feral into the house last spring (almost 11 months ago!).  My resident cat had been an only cat for 5 years.  We kept them separated for over 2 months, then slowly started introductions.  All was going well, when I rushed the last few steps.  It backfired and caused me to redo introductions.  My feral guy has come a long long way.  He too will allow petting, sits on laps for short spurts, loves to be brushed and is starting to allow me to pick him up.  Yet, he is very very territorial.  He also gets very upset when his routine changes one little bit.  He sits outside of rooms and waits for my resident cat to come out and then pounces or chases him.  No blood, but often fur. 

A few things I have used to help:

1. feliway plugins and spray

2.  Composure feline treats and liquid.  This worked very very well for about 6 months and now the effect is wearing off.  I used it on both cats.

3.  Flower essences:  I have used some by Spirit Essences as well as Green Hope Farms. 

I keep the cats separated at night, during meal times and also when no one is home.  We have left them for about an hour during the day with both cats out and they have done well, but it's most likely because no one moved!!  It seems like a full time job watching over these two.  My resident cat walks on tip toys to be sure the stray/feral is not in sight.  Resident kitty spends most of his time upstairs or if he is downstairs he is on one of the cat condos.  It makes me sad.  I believe they both want to be only cats.  They do go through periods where they can coexist, but it seems that lately the stray/feral has been very out of whack and is almost daily going after resident cat.

I know that I will never reach a point to rehome either cat.  I will just keep plugging away and working with them.  It's just a difficult process.

so frustrating and sad....sometimes I wonder if throwing a 3rd cat (kitten?) into the mix would restore some kind of balance...

I would say that they will have to accept one another soon. Try rubbing a newly washed sock on one cat and give it to the other to smell, even try swapping bowls when it comes to feeding. They probably think each other as a threat so after a while of smelling the others scent. They will get used to each other :-)

I too want to be optimistic.  As they had never fought for real, it should go well.  Sooner or later.

Good luck!

Yes, it's been my experience that all indoor cats eventually learn to co-exist, though they may never all become friends. When I took in a stray, Angel Boy, several years ago, one of my indoor cats hounded him and fought with him for over a year (I had two other cats who accepted the stray immediately). I did not attempt to separate them. They worked things out on their own and in their own time (unlike humans, cats are able to do this!). They never became great friends or snuggled together or groomed each other, but they slept beside each other on my bed and on the couch, and bird-watched at the window. When Angel died, I believe all of my cats mourned for him equally, even his former "antagonist."

I want to add that when I took my female feral inside my home last August, the 3 other cats bullied her and wouldn't allow her to go downstairs at all--one of them especially was vicious in chasing her back upstairs (ironically, her brother from a separate litter). It took about 4 months before she was "allowed" to go downstairs. She is not great friends with the other cats, and her brother still plays too roughly with her at times, but they co-exist peaceably for the most part.

I agree with that

Yep, we are going through this too, and time and patience is key.  A bit of a pun there because one of our problem cats has been Patience, mother of our 3 rescue kittens who we adopted last summer.  After being regularly fed and sheltered outside she moved into the house when the weather turned brutal and was initially quite aggressive to her own kittens and is still jealous and hissy if they intrude on "her space".  I actually didn't do anything about it other than scold her verbally for bad behavior and put her outside for a while if it was over the top, I figured they were family and would sort it out eventually, which they pretty much have.   But:  VERY important note here:  no physical harm was ever done, no injuries occurred, it was all hiss and spit and smack. 

We also have an issue with our latest rescue Ellie, who is scared of our cats even though they really try to make friends.  I've tried careful introductions through a screened window, with her in a carrier, taking a towel with their scent and  rubbing it on her while she eats, simultaneous stroking when they are in the same area, she won't have it.  So, finally I've given up anything structured and let he go at her own pace, coming up from the basement (where she mostly lives) to explore and gradually get used to the fact that hey she lives in a multi-cat house and no one is going to hurt her. She is oh so slowly catching on, to the point that she will now tolerate at least looking at the other cats from a safe spot without fleeing.  But I will say I am blessed by 3 loving patient kittens (well cats now, they are almost a year old) who tolerate her antagonism - they act like "hey what's your problem, we want to be friends" when she hisses at them.   I feel it will all work out in the end, and hopefully it will for you too.