I, Who Blocked the Demon King's Ultimate Attack, Ended up as the Little Hero's Nanny! - Ch. 23 - An act of redemption

[MangaDex]

 

[NicholasTurner]

So from what I can gather from context clues her parents were part of their hero party and entrusted the future of the world to their daughter Jenny, in order to aid her growth they somehow foresaw what was needed if not as actual material for the bow than as pieces of the journey to strengthen her for what is to come.