Is there any visa recommendations for thai citizen shengen visa ?

Got my Mrs here in the Uk on a residency visa ! She is in full time work etc got a National insurance number , registered with the NHS etc but still only has a Thai national passport with the visa inside it…. If I want to take her on holiday to Spain or Greece or even just to Germany for the Christmas markets, do we need to get any specific visas to allow this ? Where would I get the definite answers ?

I was thinking of meeting my thai partner in Europe. Which country would give her the most likely success of obtaining a schengen visa .