No, siblings do not have the "same" saliva content for DNA. TheDNA will be similar, but not exactly the same. Parents in twofamilies tested their triplets and quadruplets using Ancestry's DNAservice:insideedition.com/investigative/21784-how-reliable-are-home-dna-ancestry-tests-investigation-uses-triplets-to-find-outThe results showed similar ancestry, but with some variations.