There is not much to support my claims, but I would say that the marks on her hands are burns. Personally, I believe the whole Firelink Shrine and the people there exist outside of time, thus Andre. We know that there exists an actual Firelink Shrine in Lothric and that the only one living there is the old lady. Maybe, the whole Shrine is the final endeavor of the universe to revert back to the age of fire. We know that time had already started becoming convoluted from the first installment, so there is a possibility the Firelink Shrine in DS3 is, like, a perfectly constructed dimension of sorts to make the reversion to normal of the world possible. Plus, in the DLC, a similar thing has happened to the Ringed City. I deem the actual reality is the one we see at the Kiln of the First Flame, the world having collapsed in on itself, the Ringed City is an attempt of a Goddess to recreate life, albeit illusory and the Firelink Shrine, a place existing outside of reality created by the will of the lords that sacrificed themselves to link the flame, the Fire Keeper being the fusion of the souls of all past Fire Keeper. Sounds logical (partially, at least) to me.