Elizabeth, knowing that her sister was ill, was approached immediately upon Mary's death, and was given the Queen's ring as proof of Elizabeth's rights to the throne. Upon receiving the happy news, Elizabeth said, "This is the Lord's doing, and it is marvellous in our eyes." Finally, after all the hardships she had endured during her childhood and during Queen Mary's reign,
"My lords, the law of nature moves me to sorrow for my sister; the burden that is
fallen upon me makes me amazed, and yet, considering I am God's creature,
ordained to obey His appointment, I will thereto yield, desiring from the bottom
of my heart that I may have assistance of His grace to be the minister of His
heavenly will in this office now committed to me. And as I am but one body
naturally considered, though by His permission a body politic to govern, so
shall I desire you all ... to be assistant to me, that I with my ruling and you
with your service may make a good account to Almighty God and leave some comfort
to our posterity on earth. I mean to direct all my actions by good advice and counsel."
Here is a video from he movie "Elizabeth R" starring Glenda Jackson, depicting Elizabeth being told the news of Mary's death. Enjoy!