It really is going to depend on how she structures her taxes. I believe she'd technically be a 1099 filer so she can include line item deductions that arise from a normal course of business. Streaming equipment and software are what most people think of for that case. She could also file through a business entity like a corporation or LLC, which in that case she can probably be a lot more liberal with deductions.
1099s are meant for people who do contract work but aren't incorporated. Historically you'd think of a general contractor, plumber, electrician, etc. You'd be stupid to not just run everything through a corporation or LLC just for the liability shield, though.
If you feel like she's cheating on her taxes you fill out the reporting form(s) here:
Report fraud if you suspect an individual or business is not complying with federal tax law. Find out how.
www.irs.gov