不是B2。 我想幫她申請移民簽證。
-Then, your and your friend's total income of last year should be 125% of the poverty lines.
Calculate by yourself based on the data in this link:
http://www.coverageforall.org/pdf/FHCE_FedPovertyLevel.pdf
By the way, you should be a US citizen to sponsor your mother's immigration visa and your friend has to be a green card holder or a US citizen to be the co-sponsor for your mother's immigration visa application.