Context: In my story, I have an extremely famous young girl (thirteen at the time). Extremely famous has the meaning of probably the most famous person in the world at this time due to the fact that she has enormous wings and is billed as an angel (though she isn't; this is essentially the real world, where the fantasy I've created plays no part). Her act involves some meagre singing and dancing, which are really just excuses to gawk at her. She comes from an American circus but is Irish.
Anyway, at the end of the 1925 season, I have her giving a Command Performance in the presence of King George and Queen Mary. The only trouble is that I have absolutely no idea what the process would be at this time. Where it might take place (I have no requirements--she can be sent anywhere), who else might be in attendance and how they would be dressed, what protocol she needs to know and use, etc. Her act is so simple that, aside from her wingspan, she doesn't require a lot of space. People tend to like to see her up close and I would really like her to be presented (and that may be standard--shows what I know about Royal Command Performances of the period).
Searched for history of royal command performances, specific command performances and court appearances of different types of celebrities (for example, Tom Thumb), command performance procedures and etiquette, the history of the Variety Show, went to YouTube to watch videos of stars from the 30s and 40s being presented. The trouble with the memoirs I've read is that people gloss over the specifics and only ever mention that they attended one or their theatre company performed one. I may end up handwaving things myself once I get to this point, but in case I don't, well, I want everything in order!