My role model is Audrey Hepburn.
She was british actress.
>> She was a British actress.
- use article "a"
- British should be capitalized.

After retirement,She did volunteer work.
>> After retirement, she did volunteer work.
- she doesn't have to be capitalized.

When she fighting with cancer,she went to the somalia and did the volunteer work.
>> Even after she was diagnosed with cancer, she continued to volunteer in Somalia.
- Even though -

I think she is really great person because she spend all time to did volunteer work durinf latter year.
>> I think she is really a great person because she spent her
life helping others and volunteering.