VISA Interview financing education

Hello everyone I have a doubt regarding visa interview(financing education). 1.I have received 30000$ as loan and 30000$ is sponsored by my sister( having H1B visa) who is in USA. Hence which documents are required to showcase the same. (Is just the bank statement of my sister having balance of more than 30000$ enough or anything else is required?). 2.Has anyone used the same way to fund their studies as mentioned above because I'm little worried whether they may reject if I showcase that my sister is also in USA. Thank you