Three things hit hard emotionally in your story:

1. Sudden loss of a beloved who was so young. I feel it is grave injustice that some people die young.

2. He was a good man, a savior, and deserved to live much longer because the world needed him, both his family and his patients.

3. A girl asking her mother whether she could choose her own age after death if she died young.

And the title, "I am older than you now", culminates all that beautifully.

It is impossible to completely heal the void created by loss of someone so close and beloved. I wish you the strength and love to smile genuinely and feel pure happiness again. :)