russian wanting to visit Europe

Hi, first post on what seems to be an informative Forum. Congrats.

I am enquiring for a colleague/friend who is a Russian citizen with job, flat etc who wants to be a tourist in Europe's cities, including those in Schengen - starting with Barcelona where I will be visiting for my work.

She used to travel for work purposes over the past 5 years, including to France, so has some experience of getting those work-related visas but has now left that job.

What sort of letter could I write, as a UK citizen, that would assist her obtain a Schengen Visa, preferably a multiple entry visa?

*** I realise that I may have posted this in the wrong section. am off to explore the other sections ***