I hope that you are not one of those “age of accountability” posters that I have noticed from time to time. I say this because I see nothing in scripture which indicates that age plays any part in salvation. I do, however, see scripture which indicates that we are saved by grace alone.
Grace in scripture is bestowed upon individuals regardless of their actions or worthiness, highlighting God's boundless love and mercy not something earned, that is essential for spiritual growth and salvation.
I believe that anyone regardless of age (1 min – many years) may receive God's grace. However, God owes His grace to nobody!