Hi Lyonresh! A belated welcome to the forum

I applied and visited uk as a tourist for quite a number of times already.... Some of the documents i supplied the ukba office are as ff:

- an invitation from the sponsor saying that i can stay in his house for the whole duration of my visit etc.
- sponsor's passport (photocopy)
- my bank statements
- business permit (maybe an employment certificate if she's employed)
- recent tax payment

Basically, just supply the documents required listed in the website.

I dont think that medical insurance is needed to get a visa for uk. You will need it for schengen visa if you will travel to other european countries.

Good luck to her application