Split the beam means to land on the beam with one leg either side
of the beam, by accident of course. Very, vary painful and scary too.
I do feel for your DD, that must have been horrible. My 8 year old dd had a bad beam crash in July and she is only just getting over it. She had learned her cartwheel on the high beam and had it solidly, then there was a demo at the camp and in her exitement to show off her new skill she crashed arm and head first on to the beam. She was so embarrassed, in front of all the parents and coaches, that she just carried on as though she was fine, but later when she got to me she showed me a huge bruise and graze. ( I actually caught it on tape, to show Dad!!) SInce then she wouldn't do much on the beam, went back to baby cartwheels with her bum sticking out, I really felt sorry for her as she wanted it badly but was too scared.
Her coach just let it go and said she'll get to it when she is ready, and guess what? This week she got it back and seems okay again.
I suppose with any major trauma, like these, the girls just have to find their confidence again, I am sure gentle encouragement might help too, but they all have their own schedules.