Visitor Visa - B2

My friend is planning to visit for the summer me in California from South Africa, she got denied visa first time, but we paid for ticket a while back, so we are trying again,one more time, her interview is scheduled next month. What are ways you think she can show she has strong ties back to her country. She never got to mention the entire trip was paid for, and that all the accommodation is on me. The trip is literally just one week.

First interview went as so:

Good Morning
Good Morning

Why do you want to go to US?
Visit my friend for her birthday.

Are you student?
No I finished college.

Where do you work?
Tells where she works.

Ask for bank statements
shows bank statements

Consulate
Sorry you do not qualify.

What are ways to show strong ties back to country, she has written letter from the CEO of her company, employee leave letter and helps her father with his business and her little brothers.