This is exactly what I was thinking. Technically, the max for any bag to be placed in the overhead is 40 pounds (at least for DL, CO, & WN). The minimum lifting ability is often stated as 50 pounds. Ergo, regardless of how sweet of an old lady she was, the pax described by the OP was clearly ineligible to sit in an exit row. I can only think of one time when I narked on a would-be-exit-row-occupant... it was on a WN flight in which the pax spoke hardly any English at all. (he needed an interpreter in order to be asked to move!) On WN, it can be tempting to rat out any potential violator, as one can directly benefit by getting a better seat, but this was not the case the time I did so; the gentleman had been in a center seat.