WOW, 1st on bars is awesome! Sorry about the floor, I agree with everyone else who said it's normal and nerves (and judges/parents watching) do play a huge part in young L4's.
My DD was a 6yr old L4 last year too, and it was very difficult for her to compete in front of close seated parents. Whatever event was closest to the crowds, was the lowest score of the day, LOL! I think it is hard at that age to just remember everything in a routine. A break in concentration and not knowing what to do next in a split momment is very upsetting. You practice this stuff over and over again and I am sure they (gymmies) want to please coaches, judges and parents in those few minutes of routine time. Also, times of the meet and amount of girls in a rotation play a huge part in younger girls. My DD is not a morning glory...just can't wake up for an early morning session and is often moody. Long/big meets that have alot of girls in a rotation mean a lot of down time and plenty of opportunity to get fidgety and fatigued too. This year she is a 7yr old and now comes the understanding of scores and putting pressure on herself to do better and get good scores. When she tries really hard she gets too tense and fell off the beam more this year than last year. She also decided she wants a perfect 10 score in vault (LOL, impossible I know!) and tries so hard to vault well even though she already gets over 9's all the time she has crashed a couple times and out came the tears.
I think as your DD gets that meet experience, things will get better. Sounds like she just wanted to do things well and was afraid she did something wrong. The coach may advise her what to do next time that happens too...like missing a skill & re-grouping to finish up...sometimes they just don't know what to do when something goes wrong like that.
She'll do better next time for sure!