Can't believe how much you both have found already!
I had a quick look to see if Christina Vickers was born in England, on the offchance...the only one that showed up, was a Christina Vickers born in 1864 (this on the 1881 census) and funnily enough, she was a dressmaker.
Her father was English, and her mother Scottish...hmmm
JJ, did you try Margaret Ross? For some reason, that name was on the back of the photo.
I wonder if in 1901, Margaret was taken into care (as her mother had just died in 1900) could she have gotten "lost" in an orphanage or something?
How strange that you can't find the birth

You've done great so far!