She was on a tight final glide flying together with another glider
with a highly experienced pilot

It occurs to me that being in a tight situation with a highly experienced pilot may not be a good thing. In such a situation, "flying together" may involve a bit of mentoring, which in my experience works great at altitude. But in a "tight final" situation, I would hate to be in the mind set where I am using queues from a more experienced pilot as part of my decision making. I don't know the facts about this tragic flight, but handling a sticky situation requires 100% of a pilot's skills and focus, and in a tight situation, it seems to me a teammate, mentor or protege may be more of a liability than an asset.

I know little about team flying, and less about this particular accident, but I would think that extra-conservative margins would benefit team flying especially with pilots with different levels of experience.

Rob