[TOMT] [Book] Grief and finding a unicorn…??

I know I’m really at the end of the line when I’ve come here for answers, but I’ve had good luck asking other questions, so! I’m looking for a book to help my mom? She’s 52 right now, and she read this when she was pretty young — so I’d say maybe the 70’s to early 80’s.

The description she gave me of the book is as follows: A young girl is staying/living with an older female relative (could be a Grandma or Mother, but the only thing she’s certain on is the fact that it was an older relative.) Said relative is dying for some reason, and the girl figures out/learns that if she finds this mythical Unicorn the town she lives in has a connection with, the Unicorn can heal her relative.

While she’s looking for this unicorn, she starts bonding with a different relative ((my mom thought it may have been her dad or something?)) who is helping her find this Unicorn — all very inspired by those famous 7 Unicorn Tapestries according to mom. As the first relative starts progressively getting worse, the girl connects with the other relative more and more, and at the end when Relative 1 dies, she still ends up with someone to love and take care of her. Someone who will help her through the grief and such.

My mom swears up and down that she’s looked for this book for years and has never been able to find it — and she is a dedicated book reader, so that’s pretty rough IMO. I’ve tried some basic searches, but she said the book was already kind of old when SHE read it? So maybe something from the 50’s? I can’t be sure, but any help or suggestions would be super nice 🙂 I’d just like to give my mom this gift, books meant a lot to her in her childhood.