The thing about writing a series about a group of sisters, is that if you're doing it somewhat realistically, then you can't make them all the complete opposites. If you have four sisters they will share some characteristics, even if their personalities are very different. There will still be some personality traits they share.
I felt like writing Linden was similar in some ways to Maggie. They're both serious and kind-hearted. They tend to follow the rules and try to keep the peace between Ivy and Willow.
But Linden has a darker core than Maggie. In my brain this is because of what happened to her in the first book. After that incident, she has perhaps a shadow in her soul. She's not the happy-go-lucky type. She's sensitive and sometimes just feels sad.
Happy Writing!