Thanks for the advice...
It was really incredible - the length was maybe down to her knees, and she had a cute face. Super hard to get off the train (for work), she stayed on - probably until central London, who knows.
Maybe I'll see her around again.. if I'm lucky.
I won't be creepy. I didn't even look back, as tempting as it was!
I'll just be glad to have seen this rare sight which in itself was a blessing.