GamePass Ultimate Family Sharing (specifically for upcoming streaming service)

Hi All,

Many thanks for taking the time to read my question.

My current set up is

1 x Xbox One, my 'home' console, for which I have a gamepass ultimate subscription

2 x Android phones / bluetooth controllers

Over the last few months, My Wife, Son & I have enjoyed playing games like Sea of Thieves, with

my son using the xbox which, with the benefit of my GamePass Ultimate subscription, can play the games and have access to the multiplayer aspects with no issue, and,

My wife and I both playing on our Android phones as part of the Xbox streaming preview (xCloud).

I'm aware that, as of middle of September, the streaming service becomes part of the GamePass Ultimate subscription.

My question is this - is there anyway that my wife can still stream games to her android phone using my gamepass ultimate subscription? Can this be shared as a 'family'?

If not, having a family subscription option for a few pounds more than the standard ultimate subscription would surely make sense for Microsoft to release (they had similar for Xbox Gold in the 360 era).

Many thanks in advance

:)