Complex sentence: It is unclear when she died, with some sources giving the date as 1535 or before, when she was only around twenty-eight years old and others stating 1552, the same year that her former husband was executed for treason.
Split into simpler sentences: It is unclear when she died, with some sources giving the date as 1535 or before, when she was only around twenty-eight years old. Other sources suggest that she may have died in 1552, the same year that her former husband was executed for treason.