[tialaramex]

No, although the Pardon Power now exercised by US Presidents is indeed there because Kings had it, in Liz's case that power like any others which were once the monarch's powers to exercise as they saw fit are today exercised by "her" government which was chosen by Parliament, elected by the people.

By the time Turing was convicted that power is in effect in control of the Lord Chancellor, part of the British Government. Today although the title is the same, a Lord Chancellor would likely be an MP (ie elected, albeit not to do that specific job) but at the time Turing was convicted I assume it was a Peer (so, not elected) but chosen by the Prime Minister of the day (who is elected).

The most recent notable exercise of this power by the British government was to reduce the sentence for a murderer who (during day release) tackled some terrorist lunatic and thereby likely saved some people's lives.