If you are seeing distinctive characteristics then you will need to line breed with her as a starting point. This is obviously much slower using a female. Select a (non-ghost) male to breed to her that you think will enhance what you are seeing as different that you want to emphasise ( this is where nice normal males have a role) and go for it. You will need to keep back the babies and make more hets using a different male the following year (to keep the bloodline fresh) and hopefully by the year after you will have a het son ready to pair with her and see what you get from that. You will need to selectively breed out while retaining what you want from the line. Then rest her the year after (if she wants it - she will have earned a year off by then) and start breeding her daughters, but accept that you will make some unsaleable 66% hets along the way. When you have established that breeding a son back to the mother does indeed preserve the characteristics that you want (and that she isn't just a one off) then yo can look at naming your line of ghost and making it available to other people.