D&D General Hey what's the counterspell for fool's gold?

[le Redoutable]

My sister uses almost all her spell slots when in my surroundings by using what I was simply calling bluff;
Now I believe it's a fool's gold, that she masters to a level that I have trouble to evaluate ...
Could you give me hints to let me free from her enchantments?
I tell her things like I 'm wise but low int ( well psychology )
I think she has long term revenge under construction...