Mary I of England was the oldest surviving kid of Henry VIII, and once it became clear that her mother wasn’t going to have a son, he treated both of them like crap. When Mary’s parents divorced, she was forbidden to see her mother, and was declared a bastard. This meant that she was no longer a princess, and was removed from the line of succession.
When her dad had another daughter by Anne Boleyn, Mary was made to wait on the baby girl. In this period she suffered depression and fell very ill, which was only made worse when her dad wouldn’t let the doctors or her mother see to her.
Despite all of this crap happening to her, Mary stayed staunchly Catholic (despite Henry’s threats to have her killed), and she genuinely loved the two younger siblings that she had.
When her little brother died, he tried to give the throne to a cousin of theirs, rather than pass the crown to a Catholic. Mary raised an army and rode into London victorious, with her sister Elizabeth by her side.
She was the first woman to successfully reign as a Queen regnant of England. Even though lots of people (including her own dad, brother and husband) were complete dicks to her, and despite having the worst adolescence a princess could think of, Mary persevered and took the crown that had been promised to her when she was a child.
You go, girl!