Visitor VISA Help

[newbiefrompk]

Hello everyone,
I am helping my mother apply for her visa to the UK. She has travelled to the UK before; she has had one 6 month visa and a two year year visa. My sister is in the UK. She lives with her son and is on benefits. My mother's first cousin has sponsored her visa the last two times but this time he is not. We requested him for the following documents and he only provided an invitation letter. The documents requested were as follows:
1. Sponsorship Declaration/Invitation
2. Passport Copy (Notarized)
3. Source of Income
If Salaried Individual
a. Last Six Months or 1 Year Salary Slips (Original)
b. Contract or Employment Letter (Original)
If Business Individual
c. Business Registration Evidence (Original)
d. Income Tax Returns (1-3 Years) (Original)
e. Letter from Account to Describe Yearly Income (Original)
f. Business Visiting Card and Business Letter Head (Original)
4. Personal Bank Statements for Last Six Months Or 1 Year (Original)
5. Business Bank Statements for Last Six Months Or 1 Year (If Applicable) (Original)
6. Paid Residential Utility Bills, Water/Gas/Telephone/Electricity, Home/ Council Tax (Original)

How can my mother allow for a ten-year visa without sponsorship from any relative? Or are we asking too many documents from our relative? We can request our relative again with a short list of documents, if you think we are asking for some unnecessary documents. My mother has to go the UK to help out my sister with her son. My mother is 60 years old and from Pakistan. Your guidance will help our family through this hard time. Thank you.