Yikes that is tiny. 98 to 112 pounds. She is very short (5’ 2” or 157 cm according to media reports, though for comparison Emily King is 158 cm).
With weight, I would guess that lower weights help for stamina and endurance, but a lot of the guys with more torque and weight get to influence more to balance. For better or worse, I guess. If you’ve got a bit more heft you can place their feet as you need them. I personally (being relatively short at 5’4”) like taking lessons with riders my size. More transferable, in a sense.