Mary Tudor's claim to the throne became recognized after Lady Jane Grey's deposition through a combination of legal legitimacy, popular support, and the collapse of her opponents' backing. Mary was the legitimate daughter of Henry VIII and Catherine of Aragon, and her right to succeed was enshrined in law by the Act of Succession and her father's will. When Edward VI died and Lady Jane Grey was proclaimed queen, Mary quickly raised support in East Anglia and sent a strongly worded letter to the Privy Council asserting her lawful claim.
Mary's cause gained momentum as her supporters—including powerful nobles and much of the general population—rallied to her side, viewing her as the true heir. As support for Jane Grey and her backers, particularly the Duke of Northumberland, collapsed, the Privy Council switched allegiance and proclaimed Mary queen on July 19, 1553, to public celebration in London. Mary then entered London triumphantly, and her accession was secured both by her legal right and overwhelming public and political support.
She probably saw her mother die when she had her baby which she never saw either she probably saw me have a baby because that's how it was we were both targets they would take her sight my sight his sight my son's site... To control all of our money