Elizabeth didn’t marry because if she married a foreign prince then she might of lost all power over her country and that they might use the power for the good of their own country rather than England, for example King Philip ( Spain) and Francis ( France). Then if she married an Englishman then there would be jealousy among other great nobles and there would be issues her who had authority.
Elizabeth also hated the idea of marriage due to her other Anne Boleyn Henry 2nd wife was behead when she at age of three and she didn’t want to be like her father.She also declared at the age of 8 she would never marry then when she became queen she claimed to be married to her country.