Cubase element 10.5 license


I have a question, i actually did ask a similar question,
but i want to be shure if its possible to
use a cubase element 10.5 license with cubase
element 8.

One of my family has cubase element 6, and want
to upgrade to element 8 or 9.
She has window 7 pro 64bit.
The upgrade cost really allmost nothing, its so
cheap to upgrade with steinberg.
So can she buy cubase element 10.5 and
install cubase element 8 / 9 (64bit ofcourse) ??.
I myself have a cubase element 8 64bit, and
she can use my cubase element 8 install files,
then buy here own cubase element 10.5
, which will be download on to here usb elicenser!.
I myself wants to upgrade my cubase element 8
to max 9.5, all i need is to buy a cubase element 10.5
license , if its possible??.

Neither me or my sister want cubase element 10 /
10.5, becuase it means , switching to windows 10.
to much trouble!

Sorry asking a stupid question.
I forgot, svennilenni allready answered
similar question last time!.