I appreciate this is not the same…
I have dramatic differences in my insulin requirements depending on my hormone levels. I was diagnosed when I was four in 1977 and had many hypos and hypers going through both puberty and the menopause. The highs in particular, seemed to aggravate the experience I had with my period.
That may be what your daughter is experiencing. If she is very light, the differences she experiences at different times may be similar to what I went through and seemingly unpredictable. I found this helped me.
It may help to micro manage at least 3 days a month a different times during the month as you would to normally set basal rates. Once these are identified, she may find her carbohydrate ratios also need adjustment. By doing this slowly, it will be a lot less stressful and easier to get successful results albeit over a longer period of time.
It would be great to have a follow up, I wish you all the best