Nelson, Elizabeth I, and political legitimacy

After defeating the Armada, could Nelson sail to London and seize power?

Possibly in military terms, but Nelson would more likely pledge loyalty to Elizabeth I, already a heroic figure in his own age.

The counterfactual separates coercive naval power from political legitimacy. Even with a fleet capable of dominating Elizabethan waters, Nelson would arrive with the assumptions of his own age, when Elizabeth I had become a celebrated national monarch. A pledge of loyalty is more plausible than a seizure of power. The aside about a possible marriage is playful speculation, not a firm historical prediction.