F4 Visa Affidavits and Documents

[Harinivas]

Dear Forumers,
Can someone please explain for F4 sibling visa documents :

1. Do we need to submit just photocopy or attested photocopy of Birth certificate for me and my sister?
For all other documents like Citizenship certificate/Naturalisation do we just need a photocopy or attested?

2. I am also submitting Affidavit from my Mother.Should I submit photocopy or original affidavit?

Please help.