How do we know if we need to re-introduce cats

The players:
Sophie: 1 1/2 years old, adopted at 9 weeks old
Roxy: 4 years old, adopted 4 months ago

The scene:
We have had our cats for 4 1/2 months, and although I am resigned to the fact they will never be cuddle buddies, I am tired of seeing our first resident cat (Sophie) confined to the bedroom and the bathroom all the time. She doesn't even find her own way down to the litter box because she is afraid to go down on her own. (We lead her down a few times a day, currently)

We have finally established a litter box and food area in the attic, and this at least allows for another option, but I'm thinking it's time to do something a bit more directive. My thought is to let them switch a couple of times a day but never actually be in the same area for a while (how long?) - one cat will be upstairs in the "kitty apartment" and one downstairs in the main living area.

When Roxy is not just around the corner Sophie gets very social, roams the house fully, asks to play, and eats immediately, even though we have also set up an extra food / water dish in "her" bedroom. So I know that she's not just being reclusive because she wants to be. Roxy gives Sophie the evil eye every time she comes into view, it seems, and Roxy will chase at full speed. She is also larger and older than Sophie and is the most muscular cat I have ever known. If I were Sophie I'd be spooked too. I have not yet seen them in a full fight, but the intention is clear. I don't know if it right, but I can't help intervening and giving Roxy a "time out" when she chases. She never bothers Sophie in her bed, and rarely in the bathroom.

I know that after four months some adjustment is still natural, but when do we call a halt and just do a full re-introduction? Does anybody have experience with this, and does it really make a difference? We did attempt to introduce them correctly the first time, but I have this feeling we missed a step.

We love both our kitties, and they are both sweet with us and (most) humans. As things are, Roxy thinks things are fine, but with Sophie at only 1 1/2 years old, I have a feeling there is more drama to come. I'll post the kitties' stats here so things are as clear as they can be. Sorry this is such a disjointed message. I just think there must be a better way.

have you tried the wonders of Feliway & Rescue Remedy yet?
they're not a 'cure all' in every home, but they were here. we had a cat that was being picked on & before it went any further we introduced Feliway.
in this case I used a bottle of Feliway & sprayed all of the spots that they could mark with their faces & their sleeping areas. I also started using Bach's rescue Remedy. I would also start paying extra attention to the older cat. Corporate cuddles system! Extra attention to that kitty & then feed them treats together & play with them.

The "Feliway" we have is called "No-Stress" from Pet Organics. It is in a large spray bottle, but we have not used it consistently. We could do better about that, but it is hard to tell if it makes much of a difference. We could try Rescue Remedy, but is this the sort of stuff you have to replace every month? It seems a little pricey for that - I would be more eager if I were sure it would last a while.

Today we are just "rotating" the cats to the different parts of the house so that each cat has her "day" downstairs or upstairs. Neither place is a bad place to be, and both supplied with litter / food / comfortable places / windows but as a family we spend most of our time downstairs so the cats spend more time there too. The window views are also better downstairs, for those who would dream of bunnies and squirrels.

We are just guessing what they need right now, but there must be something to do differently. I'd like to hear more about rescue remedy. Thanks!

Okay, new development. Sophie can still climb under the door to come downstairs. The gap is wider than a normal door, but I didn't think she could still get under it (which she did handily as a kitten). If I could hear more about rescue remedy maybe that really would be the way to go. Meanwhile we'll start spraying "no stress" more around here, at least. Roxy can still go upstairs, but I also don't don't want to keep her up there all the time. As of this moment, both cats are downstairs again, and Sophie is hiding in the bathroom. (please keep in mind that she actually likes it in there.)

If we use "rescue remedy" would we use it for both cats, or just the one who's most stressed (Sophie)? I'm looking for it at a store I can actually drive to (as opposed to online) and I do not see it at PetSmart or PetCo, which seem to be the most obvious choices. There is something called "calm down for cats" that claims to be natural, made with flowers and makes the same general claims as rescue remedy. Any thoughts here? We're not truly in crisis about this, but I have a hunch Sophie would like to see more of the world than just the bathroom, even when Roxy is around.

yeah, the "calm down stuff" is basically rescue remedy. RR can be purchased in Health Food stores.
i was using a few things like this on different cats. the top cat around here was getting some for "dominant cats," while I used another to calm down others with jealous issues & especially poor Jack who was being picked on.

it doesn't work for all cats, but some people report that it stops their cats from fighting. I was putting some in their water & also rubbing it into their ears. that along with Feliway seemed to work for us & we have a 5 cat home.

if it fails, do a proper re-introduction & see how you get on. now I hate to be negative, but there are some cats that never will get along. i really hope that's not the case! i do firmly believe that we can project our own feelings into kitties, so make sure to stay calm!
good luck!

Here are the ingredients for the stuff I am looking at, which is "Good Cat" from Petco:

Contents: Proprietary compound of essences from flowers, including impatiens, HPUS and clematis HPUS, purified water. FDA registered active ingredients listed in homeopathic pharmacopoeia of the US.

Is there anything here that sounds odd or raises a red flag for anyone?

The other stuff that sounded close has 13% alcohol in it - I just think putting the cats on booze is a little extreme. I still have the feeling they're selling snake oil here with all these "calming" products, except a lot of people seem to say it helps.

I don't mean to be paranoid here, but I don't get that saying something is "natural" and made from "flowers" means it's healthy - arsenic is natural, and poppies are flowers.