Complex sentence: Andromeda's maiden name was Black until she married muggle-born Ted Tonks-this was considered dishonourable by the pure-blood Black family, and she was erased from the family tree.
Split into simpler sentences: Andromeda's maiden name was Black until she married muggle-born Ted Tonks. This was considered dishonourable by the pure-blood Black family, and she was erased from the family tree.