I find some interesting informations and I would like to share it with you :
Conserving the Umbilical Cord :
"HESONO-O: This is a ritual involving the baby's umbilical cord. When the baby's cord dries and falls off, it was put inside a special wooden box and kept indefinately. This signified a well WISH for the MOTHER-CHILD RELATIONSHIP in the future."
"Hospitals in Japan tend to save the umbilical cords after births. They carefully package the cords inside wooden boxes and present them to the proud mothers upon their departure from the hospital. Japanese MOTHERS typically CHERISH the umbilical cords, allowing the child to look at it when they're older. These cords are thought to have a STRONG LINK to the well-being of the babies, which is why Japanese PARENTS look after them so well."


So I guess long ago before the child got the DNA thing, it was the only material evidence that proves mother and his kid were connecting...
We have two options.
First option :
- That umbilical cord is from Sarada so ..What that precious umbilical cord is doing in Karin's desk ?!
Why Karin should keep and cherish that umbilical cord if she isn't Sarada's mother ?
There's no reason if it belongs to Sakura & Sarada !
It's a precious thing and I sincerely doubt that Sakura offered it to Karin to thank her after that one helped Sakura to give birth.
+ remember there's no photos of Sakura being pregnant.

+ look at her expression, she was serious about this. Karin says : My desk is a PART OF ME.
If she says that it's because there's something very important in that desk.
Something she cherishes a lot, something which is a part of HER = umbilical cord.
Second option :
- That umbilical cord is from Karin (I don't know how she got it but it belongs to her) = Suigestu :

The two options are pointing to Karin.
My opinion is : Sarada is Karin daughter.
+ don't forget that comment from Sakura :

+ Sarada looks like Karin + Suigestu :

What do you thing guys ? I think I'm crazy ...
PS : so in this case, why Karin didn't raise her daughter ?! Sakura was really pregnant ??!
Edited by olayans, 12 June 2015 - 12:50 AM.