Tier 2 Maintenance Information
Please find all of the information that you'll need there. Unfortunately it does look like that if the £800 cannot be sponsored from the license holding company that it must be in the account for 3 months prior to the application, however:
"A letter from a bank, building society or other financial institution which is officially regulated in either the UK or the applicants’ home country"
Your point 1) that you made seems valid and an educated response to take back to the "immigration advisor" that you saw. As long as your friend has the funds in a regulated and recognised financial institute and can provide 3 months worth of evidence then I think she will be ok.
Hope this helps.