Thank you for your question
My name is ***** ***** I shall do my best to help you.
Since she is your wife she already has a financial claim on you and your assets.
Please ask if you need further details
I am afraid that that does not change anything - her nationality and immigration status do not affect the position
You can certainly look into having one - but it is best dealt with by seeing a solicitor face to face - and your wife will need to have separate legal advice (also face to face)