Very interesting. I would definitely keep one back and breed it to the mom. You could be selling off something awesome and not know it. You could also breed one of them to a different normal female and see if they pass anything on.
It would also be helpful to know what males have been bred to her.
The first 2 years was a very dark striped "normal" male. Year 3 was a reduced patterned Poss. Black Belly. This year (year 4) was a spider male. Most have been "peppered", but I think the outlined alien eyes may be coming from the spider.