Actually, I think Mary her half sister died of illness. Will have to check on that. Bloody Mary was the half sister. Elizabeth did execute her cousin Mary Queen of Scots after a long imprisonment.
Man, those were bloody times. And in all the waves of wars, rebellions, plots and executions, it was kin against kin, cousin against cousin.
I discovered this item, both ironic and touching, while looking up the history. Queen Mary Tudor and Queen Elizabeth, half-sisters, ended up buried in the same tomb in Westminster Abbey. The following is their grave inscription:
"Consorts in realm and tomb, we, sisters Elizabeth and Mary, here lie down to sleep in hope of resurrection."