Minor Child Return

Have some questions if I choose to let my minor child who is ten file a turbotax return 

1) Can I create an online account even though the child is under 18 (the fine print say something about a person being over 18 to have an account/file)?

2) Would my child be able to efile without the returns being rejected? At what age can minor child efile?

3) If not able to efile is only option is to mail the return in? If tax is owed can a parent send a personal check or does it need to come from the child?