that DNA results of siblings are different. See https://news.nationalgeographic.com/2018/03/dna-ancestry-test-siblings-different-results-genetics-science/, https://genetics.thetech.org/ask-a-geneticist/same-parents-different-ancestry, and https://genetics.thetech.org/ask/ask138.

My paternal grandmother is a full-blooded Dane. Additionally, the rest of my lines go to the UK. England was invaded by the Danes, many of whom intermarried with the saxons. Consequently, I assumed my DNA would show greater than 25% Danish.

Mine showed 8% Norwegian, not Danish, and my brother's was 18% Norwegian. My remaining ancestry showed 90% UK and 2% Germanic, which was not surprising given the Anglo-Saxon settlement of England. The test was Ancestry.

Bottom line: DNA is very complicated which is also why the Thomas Jefferson/Sally Hemings DNA connection is very suspect.