Do female stray cays get along?

[Goobbee]

We recently rescued a beautiful female cat from our forest. We named her Allee. She is less than one year old now. She had three lovely kittens in the forest that we also rescued and have now placed in wonderful forever homes.
We also have our own 3 rescue cats that are now 7, 8, 9 years old. Two are boys and one is a calico girl.
Allee has made great progress being socialized in our home over the past 2 months. She gets along with the two boys ok.
BUT she absolutely hates our little calico girl, Gabbee. When we have tried to put them together, Allee lunges at Gabbee claws out and really wants to kill her. Gabbee has never been mean or hostile towards Allee.
Does anyone understand why Allee is so threatened by Gabbee. Otherwise, Allee is as sweet and kind and playful as one could wish.
Allee has been spayed and has all her shots and is in good health. We would like to keep Allee but if we cannot get a handle on this we may have to adopt her out.
Thank you kindly for your help.

[Goobbee]

Sorry - I meant to write "cats" in the title and not " cays". And I even proof read it!

[Mollycat]

A lot of people say boys are much more social than girls and easier to make friends, unless the girls have grown up together and then they can be a kind of Sisterhood, raising kittens together as lionesses do and so on.

In my own very limited experience both my boys separately just couldn't stand being an only cat and one pined and stressed and the other went out recruiting himself. My girls on the other hand have been very happy only cats, two I would never have dreamed of presenting another to. Only Sarah happily accepted when a big tom decided to move in, but it was a different story when his girlfriend from his old home followed - Sarah didn't like her at all and for a while we thought they might have to be separated.

Many people here have much more experience than me of multi-cat households though. All I can suggest is going right back to basics separating the girls and trying to integrate them step by step over weeks or months.

[Ruth B]

Female cats can live perfectly happily together, but as with any intelligent beings personality plays a big part. At the moment I have three cats, the two younger ones came as a pair from the rescue, but aren't related, and then there is my golden oldie female, who in hind sight might have been fine as an only cat, but I'd always had them in pairs and thought she was missing the one I had lost. Very quickly the young nervous female adopted the elderly female as her role model and started following her around, the young lad started doing his own thing and antagonised both the girls. I'm not sure the elderly females really likes having a little shadow, but I think she prefers it to the passive aggression displayed by the male. Cat interactions are never straight forward.

As Mollycat suggested, try going back to square one with introductions and be prepared for it to take weeks or even months, go again through all the scent swapping and sight swapping and make it so that everything to do with the other cat is associated with something pleasant like food.