Do you think there is a time when children are too young to learn about sex?

I don’t. I think that the first time they know enough to ask a question, they’re old enough to hear whatever relevant answer. For example, when my daughter was 6 she asked me, “Mom. What would happen if a bear had a chicken and a chicken had a bear?”
I said, “Ugggh. You’d have a dead chicken and a frustrated bear?!” I laughed at my own wittiness while my husband rolled his eyes, then proceeded to tell her the real deal, and why a bear will never have a chicken. She was mostly…disgusted! LOL!