Upvote:0
If you provide documentation and plans to get married, proof of your relationship and other documents, she can get a marriage visitor visa for 6 months. She can come and visit, stay with you and then you can get married in the UK as well.
The problem with this is that she has to leave the UK after her visit. Then she can apply for a family visa from Russia. And, not sure about the UK, but I guess with the Covid-19, it would be hard to plan to get married.
She can't
live in the UK for extended periods through frequent visits
extend this visa or switch to another visa
work - except for permitted activities related to your work or business overseas, such as attending meetings
And yes, if she has strong ties with Russia, and can provide all the documents like bank statements and all- she can get a standard visitor visa and come as well.