score:10
She may send it.
But it does not mean much if your own circumstances and reasons for returning to your home country are not convincing enough. If your application is strong in that sense then such a sponsorship letter can add weight to your application but on its own it does not guarantee anything.
if anyone have any tips how to assure accepting my visitor visa in any other ways I'd be grateful for any help.
Apply if you believe you can convince people your own circumstances in your own country are good enough that you'd want to come back to your life and that you can afford the trip. Don't apply only on the basis of a strong sponsor already in the UK.
Upvote:3
Anyone with whom a visa applicant has a genuine personal or professional relationship can invite them to visit. If the person inviting you to visit is in the UK, they must not be in breach of immigration law at the time of the decision on your application, or your entry to the UK.