She’s beautiful! You did a great job!
You definitely don’t want to release till spring when there are leaves on the trees and it has begun to warm up. Each squirrel is different but most all squirrels will choose a life in the trees if given a chance. Their instincts tell them this when they mature. The soft release process gives the squirrel time to adapt to the sights and sounds outside. It sounds like your girl is already doing that. The next step for you, and her, would be to leave her outside over night once the nights get warmer. After a few weeks of her being outside is when you’d open a small 3”x3” portal door for her to leave. Here’s the link with information about the soft release process.
https://thesquirrelboard.com/forums/...-How-to-Sticky
It has been my experience that once you are spending less time with them and they’re outside 24/7 they will naturally become a little more wild. Female squirrels tend to stick around more so than males. I find it helpful to place a wooden squirrel box in her release cage so she can get use to it. When it’s time for release I’d put the box up in a nearby tree. This way she’ll have a familiar home that has her scent already.
Please keep us posted on how she does.