score:8
According to this article in the British Art Journal from 2014:
[Lily] married John Boyden Barrett in 1898 and, probably because her husband did not approve, her modelling career ended. For two decades she appears to have lived a comfortable, married life, living in rented houses in various parts of London with her husband. Thereafter, her situation seems to have gone downhill. By 1930, Lily and John were no longer able to afford to rent a whole house, and they moved into a shared flat with Hetty. Frustratingly, what happened to Lily after this is not known and no details of her death have been traced. We do know that her husband died in 1952, living, like Hetty, in a state-run old people’s home that had originally been a Victorian workhouse. His death certificate lists him as ‘street singer’.
This directly contradicts the 1920 death date, and it seems very unlikely that she wound up in South America.