Why didn't catherine of aragon's daughter become queen?

Answer 1

Matilda was the daughter of King Henry I. When King Henry I died, Matilda was his only surviving heir (his other children had died earlier on). Matilda was supposed to be the Queen of England but refused to be crowned because she thought it would lower her dignity as all the previous Queens had only been named Queen because they were married to a king. She said that she was to be called 'the lady of the english'. Matilda ruled England for a few months until her cousin Stephen Blois took the throne from her and was named King Stephen of England.

Answer 2

Catherine Grey's older sister, Jane Grey, held onto the throne for just nine days, before the previous king's sister, Mary, raised enough support to force the privy council to declare her the lawful Queen.

With Mary in such a strong position, which was strong still eight months later when Jane was executed, there was practically no way Catherine could become queen.

Answer 3

She did, in fact, become queen after the death of Edward VI (who was the son of Henry VIII and Jane Seymour).

http://en.wikipedia.org/wiki/Mary_I_of_England