Thanks for your question. I will try to help.
A non-EEA national may apply for a visit visa from another country provided that they have the right to stay in the other country and have treated it as the country in which they are ordinarily resident (ie. The country in which they normally live and which they are legally allowed to live in).
The eligibility criteria for a visitor's visa is as follow, is that you need to show that:-
· You want to visit the UK for no more than six months;
· You intend to leave the UK at the end of your visit;
· You have enough money to support yourself during your stay in the UK without working or needing help from public funds
You have to try and show them that she has continuing obligations in her home country which will continue after the visit and therefore convince them that she is not a risk of overstay. Things like a letter from his employer stating she has a job (if she does) and is expected to return to continue that job, return flight tickets, evidence of continuing accommodation (eg. tenancy agreement of evidence of ownership of a property), bank statements showing the money he has available and evidence of other responsibilities that she has which will continue after the visit.
If someone will assist her during the intended stay you should ask them to go to a local solicitor to draft a sponsorship declaration in which they state the terms of his visit, that the visitor is to return at the end of and that the person assisting shall accommodate the visitor and shall pay the costs of any unforeseen expenses that should occur during the stay so that nether person will need to access public funds.
This should cost around £50+vat and you can find immigration solicitors via:-
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