There is no “correct” age to find out you’re a lesbian.
You can know you’re a lesbian from birth.
You can discover you’re a lesbian in elementary school.
You can discover you’re a lesbian in middle school.
You can discover you’re a lesbian in high school.
You can discover you’re a lesbian in university and college.
You can discover you’re a lesbian when you already have an established career.
You can discover you’re a lesbian if you’ve married a man and had kids.
You can discover you’re a lesbian as a senior citizen.
No matter when you found out that your love was for women and only women, your attraction to women is just as real and just as genuine as every other lesbian’s.