I recently read The Thorn Chronicles by Kimberly Loth. This is a 4-book series for an early teen audience.
It’s a fairly familiar plot line of good versus evil, with an eventual twist of trying to mediate and balance those forces. (Frankly, the books could use a good edit to catch repetitions, omitted words and using the almost-right word, e.g. viscous when the context suggests the right word was vicious.) I’m writing about it because within this series, the two major women characters had symbolic plant connections.
The series opens with Naomi, a sixteen-year-old girl, running away from an abusive home. While at home, Naomi gathered strength and peace working in the rose garden her grandmother started. Each chapter begins with a rose the name of which ties to the content of the chapter.
The characters age slowly, but they do age. Their save-the-world challenges are so big-stage that the reader (I, at least) must readjust when there is a reference to going to school, being suspended for a week, etc.
I’ve read that YA fiction features protagonists who are 3 to 5 years older than the target audience. Perhaps that’s the reason for the shift in the second two books.
In the third book, the focus shifts to the POV of a younger protege of Naomi’s. She was 12 or 13 when Naomi befriended her, and is now 15 or 16. The plant symbolism shifts to cacti. Each chapter starts with cactus facts, names, and/or descriptions.
In the latest book of the series, both women are prominent. Each chapter begins with a plant epigram, either rose or cactus, signaling POV.
The point here is that having signature symbols can ease transitions between/among POVs. It needn’t be plants. It could be pets. It could be something astrological, or mineral elements, or whatever your imagination suggests.
Bottom line: Consider some symbolic representation for your protagonist and/or other major characters.