Unfortunatelt, if your mother is in good health and able to work then she would not be able to apply simply on the basis of your relationship and that you are a UK citizen.
This is because she is nnot regarded as Adult Dependent Relative because she is able to look after herself and does not have an existing medical condition.
So, this means that she would have to apply independently of you and on her own. Assuming that she does not have access to £200, 000 for the purpose of investing in a UK business that she would run, then the most likelt form of visa would be a Tier 2 general visa:
As you will see from the link, this is a visa where she must be offered a job by a tier 2 sponsor who is willing to sponsor her to come to the UK for the job.
If she is not able to find a sponsor for this visa then her options are extremely limilted if she wishes to work. I am sorry.
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