I am British citizen living abroad with a Yemeni citizen wife, I want to know if I can use my bank statement for her application and want to know whether the fact that I'm British myself would make it easier for her to get 2/5/10 year visas. Is there any advice you have for me? She doesn't work and will depositing money into her account help like £30k+?
When an applicant is a non-working spouse with little or no assets of their own, it is common for their husband/wife/partner to provide the relevant financial documents in support of the application. Depositing money into your wife’s account, over and above any regular deposits you may already make, isn’t likely to help, and could even complicate matters Should I submit bank statements when applying for a UK Visa? What do they say about me?
Your British citizenship won’t necessarily make it any easier for her to get a long term visit visa - typically a strong reason for needing to make repeated visits plus a UK visa history is required How to get a 10 Year UK Tourist Visa?. However, there is nothing to prevent her from applying for one as a first visa (personally, in such circumstances I’d consider asking for a 2 year visa initially, then build up to longer term if successful).
If you haven’t done so already, reading this guide may help https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/827480/Visit-guidance-v9.0ext.pdf