What terrible advice she has been given! It used to be possible - but now that Poland has joined Schengen, the 'any 90 days in every 180 day period' rule applies for tourist visa waivers - the clock isn't reset by simply going to the UK and back. I'd strongly recommends she receives professional help - she runs a real risk of being refused re-entry if she does a trip to the UK and back. My company deals with this sort of thing - lindenia.net
Can you get a simple 90 day tourist VISA after your work VISA and how?
Yes - you can. There's a provision in Schengen law that means that after a visa has expired, *if* you are entitled to the 90 day visa free period, then you can travel freely as a tourist. If you need more information, feel free to contact me.