https://www.medicalnewstoday.com/articles/325797.php
Girls who approach puberty at a more rapid rate than their peers may be at higher risk of migraine, according to new research.
New research may have found what triggers migraine in some women.
Migraine affects children as well as adults, and statistics show that boys and girls experience the condition at a similar rate — until menstruation starts, that is.
The researchers revealed that although migraine tends to affect more girls than boys, there may be another factor to consider: early puberty.
So how about it? How many women with migraines had early puberty? The full study is here - https://www.sciencedaily.com/releases/2019/07/190711122700.htm and they don't identify exactly what they consider "early" puberty to be.
They do explain this:
"Researchers found that girls with migraine had an earlier age of thelarche (breast development) and the onset of menarche (menstrual periods) than those with no migraine. On average breast development occurred four months earlier in those with migraine while menstruation started five months earlier. There was no difference in the age of pubarche (pubic hair development) between those with migraine and no migraine."
I was probably early, but not a lot.