Where does “suster” come from?

suster (Indonesian) comes from Dutch zuster, from Middle Dutch suster, from Old Dutch swester, from Proto-Germanic swestēr, from Proto-Indo-European swésōr, from Proto-Indo-European su-h₁ésh₂-ōr, from Proto-Indo-European h₁ésh₂r̥ — blood.

suster (Indonesian): nun; nurse