says it all in the topic really.

But traveling to a Schengen state with wife and MIL, I know my wife is exempt because she is married to me, but is my MIL exempt?

"Dependant ascendant of my wife" maybe covers it.....

Bumped

My Wife has received 2x 1 year Schengen visa's from the French Embassy for about B2500 (can't remember the exact cost).

This year we were confused when my Wife received a 26 day Schengen visa from the Austrian Embassy at no cost.

I suspect the country which you intend to visit may have its own individual policy. Did your Wife and MIL receive the same length of Visa from the same Embassy ?

I have not applied yet, I am looking to find out if she has to pay. For the Swiss Embassy I believe you have to pay the documentation fee of 1200baht even if married to a EU Citizen

I am not totally au fait with the Schengen rules, but think that if your mother-in-law is totally and completely financially dependant upon you, and you can prove it, then she would qualify for a free Schengen visa, otherwise she'll have to pay.