Linn is one of the main cures in Shining Miracle Pretty Cure. She is the fourth and last to become a cure. She is a bit naïve at times, and can be a bit mentally slow, but she doesn't really care. She is easy-going, and is satisfied with herself. She is the most athletic out of the four cures, and does rhythm gymnastics in her free time, which she, a lot of the time, incorporates into her fighting. Her alter ego is Cure Bluebottle (キュア ブルーボッタル Kyua Burūbottaru?) and she is represented by the Cyanus Segetum. Her theme colour is blue. She has two alternative forms she can change into, Strawberry Symphonia (ストローブリー シムフォニーアー Sutorōburī Shimufonīā?) and Syrup Songs (シルプ ソングス Shirupu Songusu?).
Linn grew up in Varberg, a small town on the south-west coast of Sweden. She lived a very happy life with loads of friends, a loving family, and her beloved horses. She never had a horse of her own, but she took care of some horses on a riding school not too far from her home, and occasionally giving lessons to younger students. At a young age, she didn't realize the underlying problems that existed in her family, but as she grew older, they started to surface, and eventually Linn's parents got divorced.
The divorce forced her mother to move, as she couldn't afford to keep the villa they used to live in, and decided to move to Stockholm. Linn followed with her, albeit a bit reculantly; She didn't want to leave her friends behind. At the age of 13, the move was finished, and Linn transferred to Tove's class. The two quickly became good friends, and later, Linn became friends with Nora and Sara as well.
Linn has neatly styled, straight, blonde hair, which gives off an impression of sophistication. She does usually wear her hair down, but when she gets the time to dress up, she takes the time to get a complicated hairdo, which is usually some kind of braided up hairstyle. She does usually dress in neat, girlish clothes, even if she doesn't really care for what colours she wear, as long as they work together.
"With all the luck in the world, Cure Bluebottle!"
世界のすべてのラックがよければ, キュア ブルーボッタル!
Sekai no subete no rakku ga yokereba, Kyua Burūbottaru!
- Bluebottle Lucky Shoot (ブルーボッタル ラッキー シュート Burūbottaru Rakkī Shūto?) - Cure Bluebottle's first finisher. She uses her LovePreBrace.
- WIP - Strawberry Symphonia's main finisher. She uses her LovePreBrace.
- WIP - Syrup Songs's main finisher. She uses her LovePreBrace.
- Lovely Rainbow Rush (ラブリー レインボー ラッシュ Raburī Reinbō Rasshu?) - Her first group attack, and she, along with her teammates, uses the Shiny Rainbow Frame.
- Lucky Diamond (ラッキー ダイヤモンド Rakkī Daiyamondo?) - Her individual attack using the power of the Shiny Rainbow Frame, in her Innocent Form.
- Innocent Redemption (イノセント リデンプション Inosento Ridenpushon?) - Her second group attack, and she along with her teammates, uses the Shiny Rainbow Frame as well as their Innocent Rainbow Brushes. They do all need to be in their innocent forms.
Kawarunrun! Pretty Cure Kururin Mirror Change!" - Kawarunrun! Pretty Cure Kururin Mirror Change! is the official transformation phrase used by Linn Holmberg in Shining Miracle Pretty Cure.
Holmberg (ホールンベグ?) - The meaning of Holmberg is unknown.
Linn (リン?) - The Swedish name 'Linn' means 'Weak', 'Soft', 'Tender', and/or 'Gentle' 
Cure Bluebottle (キュア ヘザー?) - The name 'Bluebottle' comes from one of the common names of the Cyanus Segetum.
- Out of the Shining Miracle Pretty Cures, Linn has the best taste of what works together in clothing, and is seen several times looking through the Precards they have, and matching them with other cards than they originally belonged to.
- She is good at handling horses.
- In episode 25, Linn states that she has been riding in her home town since she was 4, but had to stop because of the move to Stockholm.