Perhaps this is a bit picky - but are we talking about some body's GRANDmother surviving the Walk? As in mother's mother?
The only reason I ask is that the Indian Removal Act was passed in 1830. The Choctaw were the first to be moved, following the Treaty of Dancing Rabbit Creek. A big part of my family were in the first volunteer wave. For those who refused to go, most were walked between 1831-1833, The other groups (Cherokee, Creek, Chickasaw, Seminole,) followed soon after, but still within this 1831-1833 time line.
There are a lot of problems with the rolls which I won't go into here and now, but I will mention that there are more rolls than Dawes - there are the Guion Miller and Baker Rolls, and the pardon lists.
However, back to the point I wanted to make, the Walk was over 160 years ago! That is at least 8 generations ago. So the probablilty of a grandparent, or great-grandparent being alive within the past 50-60 years is very limited.