OK...there are a couple difference scenarios here.
If the series she is trying to do it BWO/BWO and she falls on the first BWO, her game plan depends on how she falls on the BWO. If she gets her feet on and then falls, she cannot do two more BWOs because she got credit for the first BWO, so the third one won't count. So, she should do a different series...handstand BWO works, but as someone else says, you have to hold the handstand for two seconds...which is a long time. Cartwheel, Cartwheel works...as well as a few other things.
If she is doing a BWO/BWO and doesn't get her feet on in the first BWO, she can try the entire series again, because the first BWO does not count for a skill since no feet landed on the beam.
If she is doing a BWO/BHS and falls on the first BWO she should try the series again (assuming it is typically solid)...the same goes for if she wobbles after the first BWO...she can just take a couple dancy steps forward and start over.
This can all be super confusing...which is why all of my optionals have to have a conversation with me when they fall during their series...then I can make the decision for them, rather than them trying to figure it all out in the middle of their routine. I also make that decision based on how consistent their series is...worst case scenario is falling on the first attempt and then not connecting and/or falling on the second...you can be in the hole 1.5 just by trying to make a split second choice.