I feel as though the title of the book may have been along the lines of “The Last Unicorn” – but that book that comes up in my internet searches is not the correct book. (The over 50 year old book that was made into a movie about the unicorn looking for more of her own kind is not the correct book.)
This novel was about a little girl that travels via carriage to an unknown family member’s home. She passes through a gate of high walls. There is a mysterious gate keeper who I believe turns out to be her grandmother who is very youthful and is a main character in the book. There are geraniums at the home she ends up at and it is revealed later that the woman she interacts with is actually her grandmother…? I’m unsure about all of this. And there is a unicorn that she sees on a late night foray into the forest. I believe she and a boy save it from destruction but all of my memory about this is foggy although I’m sure I read it many times. I had a tendency to re-read books like this over and over and I’ll be very disappointed if I’m mixing plots.