Privy Council only needs a four members, when they have hundreds. (members are hardly ever retired from it. but they can only attend when invited !!)
The monarch does not have to attend the Privy Council, for it to do “royal assent” things, Instead Two members of the firm ( Spouse of Monarch,or Prince or Princess … ) can replace the monarch in the Council. The main thing the council does is present the bills of parliament to the monarch or representativea. Monarch says approved, the things got royal assent.
Other things the Privy Council does would not need the monarch or representatives in the same way… Other committees of the Privy Council…Committees - Privy Council
The Privy Council has nothing to do with royal assent. Royal assent is the process by which bills become Acts of Parliament; its American equivalent is the President’s signature under a bill that has been passed by both houses of Congress, with the difference that, by convention, the monarch never refuses royal assent, in other words, holds no veto right.
After passing by both houses of Parliament, a bill is submitted to the monarch for royal assent by the Crown Office, and normally, royal assent is now granted by a simple signature by the monarch, although elaborate rituals were used in the past.
By contrast, what the Privy Council does is submit draft orders-in-council to the monarch for approval. These rank below Acts of Parliament. Of course, the drafts have been prepared and arranged in advance by the government departments in charge of the matter, so in effect, they are instruments of delegated legislation, somewhat equivalent to regulations by government departments in the US. The titles of the drafts are read out to the monarch in a Privy Council meeting (which indeed my include just a few members, usually the ministers in question), the monarch says “Approved”, and they’re enacted. But that’s not royal assent, which applies to bills becoming Acts of Parliament.
Although I admit I must partially retract my earlier post about the Privy Council being unable to do things by itself: In addition to the orders-in-council described above (approved by the monarch, or two counsellors of state as the monarch’s deputies, in a meeting of the Privy Council, the Council can also adopt orders-of-council by itself without any involvement of the monarch.
I wouldn’t be surprised. The late Queen was known to take a keen interest in the political events going on in the country, and she would thoroughly read the papers that the government routinely sent her. In Bagehot’s words, while she did not have the power to take political decisions herself, she did have the right to be consulted, to advise, and to warn the government, and she surely made use of that behind the doors.