Why did Jeremiah Gottwald use his Geass on Nunnally? In Code Geass R2, on episode 49, when Lelouch went to Nunnally 


  who was the holding F.L.E.I.J.A. switch, to confront her and to give to him the switch, it was revealed that she has now regained her sight which she lost because of his father, Charles Vi Britannia's geass. The only existing geass who can possibly cancel out that geass was the Geass Canceller. And Jeremiah Gottwald has that geass. On the previous episode, Nunally has fallen from her wheelchair and someone helped her. So it can be assumed (though it was not really stated or shown) that Jeremiah was the one who helped her then and canceled out the geass Charles used on her, thus having her regain her sight again.


My question is, why would Jeremiah 


  use his geass on Nunnally? (Assuming that he really was the reason why Nunnally regained her sight again.) 


Was it out of pity? Since he 


  has vowed his loyalty to Lelouch, 


did he feel the need to help Lelouch's sister, knowing that she is very important to him?

Or was it included in Lelouch's plan? If it is, what will it gain him? 

Or Lelouch purposely asked Jeremiah to do it for him, again, for his sister's sake?

Or it was just a random act for Jeremiah just for the purpose of having his geass used? 

I just need some clarifications on this part. Maybe I overlooked something or misunderstood something, but any clarifications would do. Thanks.
He didn´t use Geass Canceller on her because they have never even met. regardless of that, how would he cancel her if she had no eyesight?

Either she overcame the Geass by her own or all Charles´s Geass are canceled upon his death.