She gets to decide who’s prime minister.
Seems an awfully big amount of power.
Can she dissolve parliament?
She is way more than the figurehead she is often portrayed as, but she doesn’t really use those powers. The Conservative Party picked Johnson, not the queen.
Seems an awfully big amount of power.
Can she dissolve parliament?
Yes, but convention limits the circumstances in which she can do these things, and convention has a lot of power of its own in the British system. A monarch who violated convention would put the monarchy at risk and so they would only do so if the circumstances justified it.
The current Queen has, twice, appointed a Prime Minister, without reference to the result of an election. That was in 1957 and in 1963. In both cases a conservative incumbent (Sir Anthony Eden in 1957, and Harold Macmillan in 1963) resigned suddenly on the grounds of ill health and the Conservative Party had no formal mechanism for choosing a replacement leader, which meant the Queen had to step in and exercise her 'reserve power' - but it's known that the second time it happened, she told the Conservative leaders, they needed to come up with a procedure so she would not have to keep doing this - it's not meant to be a routine way of replacing a Prime Minister.
In terms of the power to dissolve Parliament, the Queen does have that power, but today, it's more a power not to do so. During both World Wars, the Kings of the time (George V in WWI and George VI in WWII) agreed to allow Parliament to go beyond its normal five year maximum term to avoid a situation where a government would have to campaign while fighting for national survival. The condition was elections would be held as soon as it was safe to do so (an election was held very soon after the Armistice of World War I, and after victory in Europe in World War II). These extraordinary decisions to not hold normal elections required the agreement of the King.
There have been occasions in the current Queen's reign when she has had to exercise some influence by the threat she could take action if something was not done - but a good Prime Minister does not force that situation. Back in 2010, when the British general election resulted in a hung Parliament and either the Conservatives or Labour needed to form a coalition to form government, it's known that Gordon Brown (Labour leader and Prime Minister at the time) wound up telling Nick Clegg (the Liberal Democrat Leader) that he had to stop negotiating and accept defeat because it was taking too long and "The Queen expects me to go." It is probably he'd be sent a message along the lines of "If you don't step aside now, I am going to have to step in, and that will be constitutionally embarrassing for everybody," and so he did what he had to do - stepped aside. He did not force the Queen to act.
And that's really how the system works - the fact the Queen has these powers and everybody knows it, means she hardly ever has to actually use them, because people will do the right thing before she has to step in.