Introducing Ambrosia Apple, the daughter of Big Macintosh and Sugar Belle; she's big, powerful, and terribly shy. Since she's a unicorn, she's actually very physically weak compared to her family; Zap Apple can easily lift twice as much Ambrosia can, despite being half her size and one third her weight. She does however have exceptionally strong magic, so he can just levitate whatever extremely heavy thing she need to carry.
During one of her surges as a foal, she accidentally ripped to roof of the barn and threw it on the pigsty, just to give an example of just how strong her magic can get: luckily, no pigs were harmed.
But, unfourtunently, her magic dexterity is about zero. She haven't been able to do any spells aside from basic levitation, and she cannot control her it very well. Anything that requires fine …motor skills (for lack of a better word) has a tendency to be very sloppy and shakey. For example, she usually uses her mouth to write with, because her field-writing looks like its done by someone who just learned how to levitate a quill.
As mentioned, she's quite shy and prefers to not interact with strangers. Her best friend is her cousin Zap Apple, which is one of the few ponies she's completely comfortable with. Unsuprising, seeing as they've known each other literally their whole lives. Despite not being able to talk to others without turning into a tomato, she has a tendency to crush on a lot of ponies. One of Zap Apple's favourite pastimes is gently teasing her for it, and trying to encourage her to talk to any of them. And setting up blind-dates which almost always fail spectacularly. Zap is determined to find the one for Ambrosia though, so she continues to try.