Okay, with the hint. Difference in age between your sis and bro is 12 yrs, because the difference between your brother and you is 3. So difference between you and your sis as the middle child would be 9 yrs.
Four years after your sister was born, she was 4. So you would be 13. 9+4=13.
THREE years ago you were four times as old as 13. So 13 times 4 is 52. 52+3 would put your age at 55.
So with that previous info, your brother is 58, and your sister is 46.
When your sister was born, you were 9. You were twice as old as 9 three years AFTER you became as Christian. 2 times 9 is 18. 18-3=15, so you became a Christian at 15.
Soooo...
- How old am I? 55
- How old was I when I got saved? 15
- How old is my sister? 46
- How old is my brother? 58
Did I win?

I was only 4 months late...