她12岁时首次登台。
She first appeared on stage ___at ___the ___tender ___age ___of 12.
她14岁时遇到了我的父亲,并且很快知道这就是她想共度余生的男人。
She met my father ___at ___the ___tender ___age ___of 14, and she soon knew that this was the man she wanted to stay with for the rest of her life.
他16岁时开始了他的职业生涯。
He began his professional career ___at ___the ___tender ___age ___of 16.