system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: So what powers does the Queen of England actually have? Does she really have authority to do anything?
gpt
The Queen holds the power to deny assent. This is the equivalent of the POTUS veto power. She has only ever used it at the request of the Prime Minister, but she does technically have the power to use it on her own. 

The Queen also technically has the power to force a new election of Parliament if she feels it is corrupted. This power was used in the 1970s in Australia to force a re-election by her proxy in Australia. This power has also been heavily limited in laws passed in 2011 by Parliament. 

The Queen is the Commander in Chief of all her armed forces. So the UK military and every military division held by the Commonwealth nations that has "Royal" in the title are under her command. She has never (or at least  rarely) ever issued a direct command and instead relies on Generals that act as her proxy but she has the power to command the troop in the same way that the POTUS has the power to command US troops. And like the US she cannot declare war, that is done by Parliament for the UK like it is with Congress for the US. 

She and Royal family also act as the top level ambassadors, and approve the appointment of all ambassadors. This is a function like what the US President does.