@QueenIU As long as the body is not disturbed and in the right conditions, the hair will remain in place. For example look up the hundreds year old peat bodies in Scandinavia and Ireland. Also the mummified remains of saints in Asia.
This hair tutorial video on Viking hair uses a dead body from a bog body from 280 B.C.E. has a full head of hair and the woman in the video shows you how to braid your hair like the ancient woman's hair. She even show the museum body at 6:57 if you want to skip the hair tutorial.
https://www.youtube.com/watch?v=Jj1mPtlmTZU
Edit here's a second hair video by the same person.
https://www.youtube.com/watch?v=puzgpBoesss
My favorite is the Scythian warrior hair style from a body found in a burial mound in Mongolia