Sounds like her chaotic approach is having a negative impact on your wellbeing.
One approach that may help her is to discuss her priorities with her. You could approach it with something like 'I'd like a chance to discuss with you what activities I should be focusing on to best support your key objectives' or something similar.
This would give you the opportunity to ask a few questions to better understand what's important to her, and also what kinds of things are stressing and frustrating her. She may tell you a lot, or not much at all. It would also help you to come up with a set of prioritised activities that she has agreed upon. While not ultimate protection from chaos, it would at least give you some ability to focus on a list of tasks to do first.
Also, you will have the comfort of knowing that what you are doing is the most important activities to support her, and you are therefore doing everything you can to reduce her stress.
If you are already doing this and she's altering priorities on the fly, then that's a much deeper problem.
Submitted by beesknees79 on 
help her prioritise
Hi Beesknees,
Sounds like her chaotic approach is having a negative impact on your wellbeing.
One approach that may help her is to discuss her priorities with her. You could approach it with something like 'I'd like a chance to discuss with you what activities I should be focusing on to best support your key objectives' or something similar.
This would give you the opportunity to ask a few questions to better understand what's important to her, and also what kinds of things are stressing and frustrating her. She may tell you a lot, or not much at all. It would also help you to come up with a set of prioritised activities that she has agreed upon. While not ultimate protection from chaos, it would at least give you some ability to focus on a list of tasks to do first.
Also, you will have the comfort of knowing that what you are doing is the most important activities to support her, and you are therefore doing everything you can to reduce her stress.
If you are already doing this and she's altering priorities on the fly, then that's a much deeper problem.
Hope that helps
Kev