Her full name is Tana Tucana Arcana, but she prefers to be called by her middle name only. She is a chatterbox who loves birds, ESPECIALLY toucans. Her CutieMark and name are related to the toucan constellation, which she has a special connection with. Her special talent is astronomy with a side gig as an ornithologist/magical bird caretaker. Her house has an aviary and star-watching tower.
She loves to accessorize with her favourite bracelet and a matching tail bow, and if either accessory gets lost, she becomes upset and searches until it is found.
She doesn't have many friends because she is bad at conversation (big info dumps, interrupts because she doesn't know when it's her turn to speak, and voices her thoughts out loud a little too much.)
However, she gets along very well with parrots and toucans, who love to chatter with her. Tucana is in her element when she is surrounded by talkative birds! (it also helps that she understands what they're saying, and they understand her)
She is particularly happy when she goes to noisy parties with plenty of dancing and singing. One of her lifelong dreams is to dance at her birthday party to all of her favourite songs remixed with all of her favourite bird calls.

Her only consistent non-bird friends are Valencia Orange: https://www.furaffinity.net/view/62627476/ and Pavo: https://www.furaffinity.net/view/63516857/

She has undoubtedly crossed paths with Fluttershy and talked her ears off about birds. I imagine Fluttershy politely avoids her (though she is happy that somepony is so passionate about the health and well-being of birds!)

A healthy outlet for all that chattering would be writing books, but I doubt Tucana would ever be able to publish her rambling works without a strict editing process.

This is a lot of exposition for a background character, but sometimes that's just the way my brain works.