It's up.
https://www.amazon.co.uk/dp/B076KB1C8H/ref=sr_1_sc_1?ie=UTF8&qid=1508424244&sr=8-1-spell&keywords=susters+sussex+border
It's book 9, do we need to read books 1-8 for this to make sense? Does it spoil any of the others?
J
All the books are linked, but they work as stand-alones, mostly, except where there are paired sequels. ;Riding Home', for example, is the follow-on to 'Ride On', and 'Dancing to a New Beat' follows 'The Job'. There is a pool of characters who pass through several of the books, but knowing who they are isn't crucial.
What I do is write almost entirely in first person, but not FP omniscient. That means that the narrator only reports on what they see and hear, which allows me to "see" an event from multiple viewpoints. As an example, a unifying plot element is a murder. The viewpoints I have set up different books/stories for that are:
The victim, as far as the start of the evening in question.
A friend of a friend, who helps trigger a proper investigation.
The police officer tasked with body bag duties.
The youth worker who helps organise the funeral.
Two separate colleagues who watch the damage done to the first police officer by PTSD and guilt.
I tend to write about characters rather than relying on Twisty Plots, partly because TPs are not my forte, but mainly because writing character-driven stuff is, IMHO, easier. Once you've established the character, they write themselves.
Your quote is about 'Sisters', from 2017, which is completely self-sufficient as a book. I wrote "Cold Feet" seven years ago, and the main character has a sister who is quite important in the plot. "Sisters" is her story, and can be read without knowing the 'Cold Feet' part as [Venn] it overlaps rather than eclipses.
My first book REALLY shows my lack of experience, but I still like it, clunkiness and all.