Probably Elizabeth would marry during the reign of her sister Queen Mary.
In the way that Philip had suggested to his wife, Elizabeth needed not a warder, but a husband with an iron fist. None of the English candidates was suitable [Edward Courtenay, Earl of Devon (c. 1527 – 18 September 1556), first cousin of Henry VIII; Lord Maltravers, Henry FitzAlan (1538–1556), son of Henry FitzAlan, Earl of Arundel (1512-1580) and Katherine Grey, aunt of Lady Jane Grey]. Elizabeth resided at Woodstock during the time which Mary's marriage to Philip was celebrated and consummated and a child confidently expected. Suddenly Elizabeth was summoned to Hampton Court by her sister to witness the birth of the prince who would make her politically irrelevant. This reconciliation was encouraged by Philip. At last she was admitted to Mary's presence at Hampton Court, and to an uneasy meeting on 21 May, intended to achieve reconciliation. The pregnancy was false, and her husband, who now in effect deserted her, distracted by many other imperial designs, began to see in Elizabeth, now almost beyond question the heir to the throne, a means of keeping the succession out of the hands of Mary, queen of Scots [betrothed to the Dauphin François de France, later King François II]. Paradoxically, Philip from now on kept Elizabeth, and her hopes of succeeding to the throne, alive. In October 1555 Elizabeth settled back at Hatfield, but soon she was at the centre of fresh plots, the Dudley's conspiracy of 1556, which once again involved the Earl of Devon Edward Courtenay, and in which she may have been more actively involved than in 1554. However, it was Philip, now in Brussels, who gave explicit instructions, with which Mary complied, that Elizabeth's probable guilt should not be investigated further. As a precaution, Sir Thomas Pope, a privy councillor, was installed at Hatfield to make sure that she behaved herself. Now the best way to control Elizabeth would be marriage to some foreign prince.
The perfect candidate chosen by Philip was his cousin, Emmanuel Philibert (1528-1580), prince of Piedmont and duke of Savoy, a diplomatic pawn squeezed between the Habsburg and Valois monarchs and from Philip's point of view a perfect consort (Carolly Erickson).
I would have another suggestion: Sigismund II Augustus of Poland (1520-1572).
Previously, in 1546, he was pursuing an english marriage with Mary Tudor, daughter of Henry VIII, but has not been realized.
Widower of Barbara Radziwiłł (1520-1551), Sigismund II Augustus, just to go against the will of the mother Bona Sforza (1494-1557), returns to the design of an english marriage, this time with Elizabeth.
The young Lady Elizabeth had golden red hair, eyes dark brown, nose ridged or hooked in the middle, lips rather thin, and cheek bones pronounced. Her hair was also probably naturally curly or at least wavy. She may well have had freckles on her pale skin, but like all ladies she would have taken care to avoid getting the sun on her face. Elizabeth also had exceptionally long fingers, possibly made even more striking by long finger nails. The Tudor period was an extravagant period, and vanity was perhaps a prime ingredient. Court life was flamboyant and people dressed to impress.
«Her face is comely rather than handsome, but she is tall and well-formed, with good skin, though swarthy; she has fine eyes», wrote the Venetian Ambassador, Giovanni Michiele, in 1557.
While Bona continued to lobby against the marriage and instead proposed Archduchess Catherine of Austria (1533-1572), sister of Sigismund's first wife (this marriage was a purely political union), the project liked much to Mary and Philip. Kraków was a court very rich and sophisticated, but, above all, on the edge of the world, far away from London.
Sigismund II mediated for twenty years between the Catholic Church and the Protestants. The King's marriage was a matter of great import to Polish Protestants. The Protestants hoped that Elizabeth would have a strong influence on the king and thus bring about a breach with Rome at the moment of a religious crisis and struggle in Poland. Sigismund's reign was a period of internal turmoil. He saw the introduction of the Protestant Reformation into Poland and Lithuania, and the collapse of the Commonwealth's acquisition of Livonia with the consolidation of the Lutheran power in the duchy.
In April 1557, Elizabeth's health deteriorated and she was tormented by increasingly frequent ailments. In Kraków, on 24 September 1557, as a result of a fall from a horse, the Queen Elizabeth died. There was a suspicion that she had been poisoned by the Queen Mother, Bona Sforza.