About the single loss, I think it was a mental issue: I totally agree with Minotaur indeed; the pressure to be the #1 in the team and the responsibility to win after the 1-1. I think Sara was worried about Robi's physical conditions too, and she felt forced to win to not cause her too much stress. She seemed so tense.. And I think the captain didn't help her properly: nobody can motivate and encourage her like Pablo! In this situation her game disappeared.. where was her forehand? This is my poor opinion.
Anyway, she must get used to the pressure: there will be much more of it in the next few months.. C'mon, Sara you have to cope with that! I hope Pablo (and Robi too) could really help her.. She needs confidence.