As before, I must preface this by saying that only if you as the parent/adult are already saved  
can you truly answer a child’s questions regarding salvation. 
Only God can guide your words to speak appropriately.
6. How does being saved take your sins away? 
and
 7. Can a person be saved without asking Jesus?
I’m taking notes, Momma!
{I have not personally ever heard small children ask these questions, and some of these thoughts may be a little hard for very small children to understand, but I pray this can be a launching point for your own study into how to answer your own sweet babies.}

When you understand that you have sin in your heart and believe what the Bible says about why we have to be saved to live with God in heaven and you make the choice to ask Jesus to save you , then Jesus takes away your sin. He does that by being a substitute. When you do wrong, you have to be punished. But if someone else takes your punishment [maybe a friend gets a spanking or put in time-out FOR you], that is a SUBSTITUTE. that friend takes your wrong as his own responsibility,  and that is what Jesus did for us! When He came to live on earth as a baby and then grew up without ever sinning and then died on the cross, He became our SUBSTITUTE. Because he was not guilty of any sin, as we are, God allowed Him to take our punishment. He took the responsibility for our sins.

The Bible tells us very plainly that no one can enter heaven without accepting Jesus’ SUBSTITUTION. In John 14:6, Jesus said: No man cometh unto the Father [lives with Him in heaven] but by me [trusting Jesus]. And in Acts 4:12, the Bible tells us this about Jesus: Neither is there salvation in any other: for there is none other name [JESUS] under heaven given among men whereby we must be saved. We cannot be good enough or go to a certain church or be baptized to help us get to heaven. Jesus is the only path that leads to living with God in heaven forever.
Some Scripture Reading:
I Corinthians 15:3,4
II Corinthians 5:17-21
Galatians 4:3-7
Ephesians 2:4-9
Titus 2:11-14
{There are many more Scripture passages that deal with all of these salvation questions, and only individual Bible study can help you find them all. I have only tried to include a few passages to help you get started.}