Final answer:
Mary could never become an absolute monarch because her newborn Catholic brother was set to succeed the throne after King James, amid strong anti-Catholic sentiment and Parliament's tight control over the monarchy, including laws ensuring a Protestant lineage to the crown.
Step-by-step explanation:
The likelihood of Mary becoming an absolute monarch was nil, largely due to the religious and political context of the time. When the Protestant King James I of England, also James VI of Scotland, died, his lineage included a Protestant daughter, Mary, and a newborn son from his second marriage to a Catholic queen, who was being called James III by some.
The birth of the boy, a Catholic, meant that he would succeed James to the throne, not Mary. This situation was inextricably linked to the religious turmoil that England had experienced, with Protestantism deeply embedded in the nation after the Act of Supremacy in 1534, which established the Church of England with the English monarch at its head, severing ties with the Catholic Church. Consequently, Parliament had fears of a Catholic, or a 'Papist', taking the throne and possibly reversing the religious reforms and independence from Catholicism.
Moreover, the Glorious Revolution, which took place in 1688, brought William and Mary to the throne as joint monarchs and solidified Parliament's power, limiting the range of actions an absolute monarch could take, thus enforcing that no Catholic could become a monarch as per the Settlement
The context of the time, including the sentiments against Catholicism and the established laws and customs of Parliament, played a critical role in determining the ruling monarch of England. This historical background, coupled with the political conditions set by Parliament such as the Triennial Act and other restrictions on the monarch's power, meant that Mary was precluded from becoming an absolute monarch.