B2 vis for mother

[immhlp2]

Hi, I am a US citizen. I would like my mother to come visit, she has been here two times prior but her visitor visa has since expired. She will live with me during her visit, but her traveling expenses will be borne by my brother with whom she lives in India. In the question where it asks - "Person/Entity paying for your trip', she can put in his details, correct? Do I also need to furnish my bank statements, etc if he is paying for her trip? He is unmarried, originally they were planning to visit together, but I am thinking this will be inadvisable because how would they establish incentive to return and strong family ties back to India?
How to purchase the health insurance for her visit? Thanks!