The fact that she receives a 1099-MISC means she is not a common law employee of the payer (assuming there is no misclassification of the status).  You still need to evaluate whether her activities rise to the level of §162 trade or business and, therefore, whether to report the income on Sch C or Line 21.  If it is a Sch C business, the income should be eligible for QBI so long as all the other conditions are met.