Traveling to Europe with Thai wife, she is on 2 year multi entry Schengen visa.

I have screwed up with the flights. We will be in Europe for 91 days, tried to change tickets, no go.

How anal are the authorities on this issue?

I could try get her a visa for UK and just go London for a few days but that's a lot of hassle to go get a UK visa.

Really depends on the memberstats,  some give warnings, some give fines.  I would be more concerned about it being used against the applicant in a future visa application (overstay is overstay and not welcomed). But there too I wouldn't know if the visa officer  rushes it off or makes a big deal out if it. 

 

Is a short trip to say Turkey (visa free for Thais i believe) an option?