如果你是独生子女,你母亲是一个人,那可以直接申请elderly dependent visa,一般都是直接给永居。
http://www.visabureau.com/uk/elderly-dependent-visa.aspx
This visa exists for individuals who are present and settled in the UK to bring their elderly dependent relative (parent or grandparent), in certain circumstances, to join them in the UK.
Elderly Dependent Requirements
The elderly dependent is a parent or grandparent;
The elderly dependent is wholly financially or mainly dependent on the relative present and settled in the UK and has no other relatives; in their home country with the ability to provide adequate support;
If widowed/made widower the elderly dependent is 65 years of age or older;
If travelling as a couple one of the elderly dependents is 65 or older;
The relative present and settled in the UK must be able to support and accommodate their elderly dependent without recourse to public funds.
In certain exceptional circumstances other relatives may be considered as elderly dependents, please contact one of our consultants for further clarification regarding this.
Conditions of the Visa
Usually a successful application would usually result in the issue of Indefinite Leave to Remain (ILR).