I've never seen or heard of her either. I'm not sure where Gypsy got her to add to the list (I think Gypsy & I even talked about it & she wasn't sure either... please correct me if I'm wrong, dear!).
In the "early days" when Argies & other ponies first started turning up, there were a lot of lists & websites with information but no pictures. As those "new" ponies started to become more common, the pictures took over & some ponies on lists never appeared. Back then digital cameras were not widely available & picture quality wasn't always great, so it was easy to mistake one thing for another due to a weird picture. Those are a few possible explanations.