Welcome to Writing.SE Rockhopper!
Here is a link to an older question that you might be interested in: What are good places to post your work where it will be read by others?
The question is locked though, for the following reason (no emphasis added):
This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: help center.
Looking at the help center - What topics can I ask about here? you can see that Proofreading requests and requests to critique your work are off-topic here. So we can't directly help you by providing feedback on what you can write or how to rewrite something so that it sounds better. That is just too subjective for the site, but the linked question should give you some ideas for forums where you might be able to find that sort of help.
What we can help with on the other hand is the process. If you have questions about what to keep in mind when getting your book printed or self-binding it for example, or if you want to know something about general guidelines for dividing your book into chapters, what to do about the "blurb", how to keep your motivation high, what tools or software you can use, ...
All in all, if you have a general question about writing that you think would apply to more than just your one book, then by all means: ask it here. We would love to help you with your project - and we would love to use this chance to help others with similar questions. But questions about writing a critique for single chapters or something like that from your book would be too specific and unlikely to help other future readers, which makes it off-topic on this site. There is a line there that's sometimes really fine, so I'd recommend making it clear how your questions that you want to post on this site are relevant to a bigger audience than only you.
We can't discuss your specifics, but we can for example answer what "normal guidelines" there are for constructing a story with such a premise, what typical pitfalls there are, what topics to keep in mind - and not write into the book that your loved ones will read, ...
I am sure there are other people who would love to read something about such a project and it shouldn't be too uncommon among writers to have little writing projects for their loved ones, which means the experience should be here already.