This story has a rich young lady who goes to a patent office where there are six other young ladies and somehow they all try to solve a murder.
I didn't have to do much ploting to understand the problem. Two separate stories that converge occasionally and when they do you have to coordinate seven characters even if it's only directly from one characters' point of view? That doesn't work.
The second thing I realized is that most of the young women would have to do other things with their time besides sit around. One could go along with the rich young lady, not all of them.
The third thing is that the rich young lady has two young men who might be interested in her. One gets two appearances and the other gets three. They either need to be cut or actually be part of the story.
There. I know the problems.
Here's the stuff that might be important to readers. Don't confuse the narrative unless you know that you're doing so and you have a point. I have no reason to do so. Some say never to do so but I believe a lot of different approaches can make a good story.
A linear plot with one or two mains interacting with things means it's easier to flesh out the details. When I say linear, I don't mean one thing leads to another or chronologically. I mean that scenes connect even if they take place at different times or the correlation isn't immediately evident. A random scene here or there that doesn't immediately connect is cool. Ten might be a problem unless you have a point. There should be connections if things are going to be easy. A book can be this complex thing with many characters and changing to that characters' point of view and that's great but that might not be the way you want to go to write a straight forward story. An epic tale yes, but not something that should have a simple series of events.