The various breeds people have suggested before definitely include sheltie and spaniel. Some suggested Australian Shepherd (but she is too small).
Also Papillon/Sheltie, American Eskimo, Beagle, you name it.
I have only ever once seen a photo of a dog that looked anything like her. It was soon after Lilly passed and I was browsing sheltie mixes on petfinder, and made the mistake of looking outside Canada. I saw a 12 year old female at a high kill pound in Ohio that looked sooooo much like her--the same eyes and everything. She was unsocialized and had apparently been running loose in the rural area for months.
I inquired about her and found that the pound did its euthanasias every single week and the next one was scheduled for a few days from then. So I made a plan to go get her. Another volunteer was going to drive me. But as it turned out she got scared and bit someone while being vetted by a rescue that was contemplating pulling her and she ended up on the run again for months.
I told them to contact me if they found her again, and they did. It was a lot tougher then because I didn't have anyone to take me but I was forming a plan when the very best miracle ever happened: they emailed me to say not to worry but that the couple that had found her and tamed her had come in to adopt her = )
12 years old and unsocialized in a high kill pound--the odds were certainly against her. It was such a wonderful outcome. All I wanted was for her to be safe. I was hoping all along that someone from her area would adopt her and it worked out against all odds = )
Anyway, the point of that long-winded story is that in all my browsing of petfinder, and all my volunteering at shelters, I have never seen a dog who looks much like her--just reinforces how unique and special she was.