I don't know that much about separation anxiety and the best ways to treat it - but if she gets overly upset - and especially if she's messing up your stuff while you're gone, I'd put her in a crate.

And I'd put her in a crate periodically even when I'm home - even in the same room, or out in the yard. It should be her own place to be. Special for her - with no kids visiting her little hideout, etc.

It should be her safe place to be, not a "punishment"...

But again, that's standard crate training so it might have to be adjusted according to separation anxiety situations.