Applying for B2 Visa

[cshelp]

Hi, My Wife is a homemaker. She needs to apply for a Visitor Visa to visit her younger brother at Boulder, USA. Her brother is studying at Boulder University. Her brother is undergoing a surgery in the month of Oct. So wants to be there i the month of october. what should the Invite Letter from her brother look like.

Please advise. Appreciate your suggestions in advance.

Thanks

[immihelp]

It should list the circumstances just like how you described here.