Hello house, I have a UK visa and I applied for my mum to travel with me to the UK(total budget GBP1,800) but she was refused. I will be covering all her travel expenses and I wrote a cover letter stating all these also attached my bank statements. She is retired and gets upkeep of N200k monthly from me and also earns from pensions(about 300k a year) plus some other cash gifts from other relatives, her closing balance at the time of application was over 800k. As a result, I stated that her yearly income is N2.6m and that she spends 110k monthly.
I also attached a cover letter to her application, stating that I will be covering her expenses and spelling out each payment that was sent as upkeep and by who, I also explained all deposits over 50k.
Please help review this refusal letter and how I can better address this in the future.