Mouse shunned by others
Less than 2 months ago I got 5 female mice to live in my 40 gallon breeder tank. Two wheels, lots of different hides, scatter feeding plus many tall seeds to climb and eat. They did do some squabbling but that's normal, especially in the beginning. I saw lots of popcorning the first week and everyone was content for about a week and a half. Everyone slept all together in the nest they made, nobody was a single target of anything yet.
One of my mice (white) seems to be the only one completely unafraid of people. At first she didn't go near me but wouldn't bolt like the other - just move away slightly. It then escalated to her crawling in my hand, being handfed, and routinely be handled by me. One day I noticed that she hardly ever leaves her wheel other than to eat or drink. She would sleep on the wheel everyday. I was concerned as to why she wasn't sleeping with the rest of the group. I found my answer very shortly. She slowly walked into the nest and was promptly chased out and squeaked at. She ran to her wheel and ran very fast (probably a stress behavior.) That's when I saw a small new scab of tried blood (maybe 2 days fresh.)
I immediately separated them. I put the four into a very large bin (bigger than my 40gal tank) and gave them lots of hides, scattered food and hoped for the best. I remembered one of them (grey) seemed to focus much more on nest-making and burrowing so I thought she'd be a good match for white so she won't be alone. I put white and grey in the original 40gal tank and waited a few days. They never fought and sniffed each other a few times. They did NOT sleep together once. Just when I thought everything was settling down, grey start showing dominant signs and began nipping at white - not hard biting but the squeaking and biting scared me enough to put grey back in with the other 3 in the bin.
The 4 of them get along pretty okay. They all sleep together and occasionally chase, squeak, and show very dominant behaviors but also don't mind each other and get along most of the time.
Today after work I tried the vanilla extract + neutral territory method on one of the old mice (light brown) and white. It went horribly. The mouse was very stressed which resulted in her biting and hunting down white aggressively. It was very hard to watch and I promptly separated them and now they are 4 together + one along again. I understand that I should have gone slower and that this was probably expected. I regret how I went about things.
What should I do with white? She clearly seeks out company (curious about the other mice and wants to be close) but nobody seems to want to bond with her. Feeling stuck.
Advice for white very much appreciated! Willing to try anything but losing hope.