There's a book I saw recommended as being a "must read", in one of PsychCentral's "Ask the Therapist" columns, for anyone who has a family member with a mental illness who does not acknowledge they are ill. The title is: I'm Not Sick, I Don't Need Help. (I believe it is available for purchase on Amazon.) Here's a link to a review of the book:

A review of "I'm not sick, I don't need help!" - Friends for Mental Health

Here are links to some articles, from PsychCentral's archives, on this subject as well:

https://psychcentral.com/lib/how-to-...sorder-part-1/

https://psychcentral.com/lib/how-to-...sorder-part-2/

https://blogs.psychcentral.com/careg...rsen-symptoms/

https://psychcentral.com/blog/how-to...essional-help/

https://psychcentral.com/blog/11-way...-denial/?all=1

https://psychcentral.com/lib/the-ess...lity-disorder/

I wish you both well...