Isn’t it rather cruel to visit sins of those who lived long ago on an innocent baby who has done no harm to anyone?
It’s even more cruel to require Perfect Righteousness to endure the presence of evil even a short time. We are blessed that by His grace we all have opportunity to have fellowship with Him through faith in Christ.
Since all of those sins have been paid for by Christ, even that little girl before the age of accountability has an assured eternity future with Him, but as a person with volition, once she becomes aware of Him and should she reject the salvation made available to all, then she will simply remain in that state of spiritual death until the Great White Throne Judgment, where even her election and works shall be judged in righteous judgment.
It is only cruel in the eyes of a person who has a fundamental problem with righteous judgment, thinking forgiveness may occur without judgment and still be righteous, even independent of faith in the salvation provided by Christ.