Chris wrote:

Many employers don't allow employees to choose where to store files.

Did her school provide her with VPN access to their network? Otherwise,
they don't get to choose where are her files that she sends them (from
her offline or online storage across the Internet to their "safe"
storage service). Unless they setup a VPN for her where tokens are used
to validate her endpoint as authorized to connect to their endpoint and
what privileges her connection gets, and where she could then open and
edit files that remain in-place on their intranet hosts (except for the
local buffering in the word processor to allow it to work on the opened
file), they have no control over where are copies of those files on her
end (offline on her computer, online in a OneDrive, Google Drive, or
Dropbox account, and will get transmitted via Internet back to wherever
is their "safe" storage). If not using a corporate-grade VPN to let her
connect to their intranet hosts, the files will be wherever she wants.
Relying on HTTPS to encrypt the transmission still does not control
where *she* decides to store the files.