Win 2-1: No damage done, will all come down to Ukraine tomorrow
Lose 1-2: Not a disaster, would come down to sets/games if we beat Ukraine 2-1
Lose 0-3: Would be a disaster
I would think that once Heather wins ( yes, Hev, you will ! ) we will stick with Joss and Anna for the doubles today.
The one question would be bringing in Heather ( and they might still want to see this today ), but I still imagine that's more of a thought for if it's 1-1 vs Ukraine and the doubles is a group decider. And resting Hev after her singles is clearly a consideration.
A lot would depend on how they are all performing out there, day to day.