AnnieCL's list "Girls Names with Long Vowels" of 3 great name ideas: Tegan - Waverly!

Girls Names with Long Vowels

Tailored Tegan is a Welsh name, developed from the element teg meaning "beautiful, pretty". Sweet but tough, is interpreted to mean "darling, or favorite", and is also the Welsh word for toy.
 
Pronounced as TEH-gan in Welsh, but TEE-gun in English, Tegan is outranked in the US by the similar Teagan, which is both a variant of Tegan and has its origins in an Irish surname.
 Musicians and twin sisters Tegan & Sara helped popularize the name, as did a character in Doctor Who back in the 80s.

Tegan

Dinah is a charming, underused Old Testament name with a rich literary and musical resume. In the Old Testament, Dinah was the beautiful daughter of Jacob and Leah and while some conflate her with the Biblical Adinah, they are in fact different figures.
 Meaning "God will judge", Dinah is the heroine of the best-selling Anita Diamant novel The Red Tent, and is also a central character in the George Eliot novel Adam Bede, where she acts as a moral center. In the classic film The Philadelphia Story, Dinah is the heroine's sassy kid sister while it also appears in Alice in Wonderland as the name of Alice's kitten. 
 One important thing to note is that "Aunt Dinah" has been used as a racial stereotype, from the character of the cook in Harriet Beecher Stowe's Uncle Tom's Cabin. It may also sound too reminiscent of the American diner in some accents. 
 The name Dinah was adopted by two great singers: Dinah Washington (born Ruth) and Dinah Shore (born Frances).

Dinah

Waverly, with its literary resonance and lilting three-syllable sound, could well become the next generation's successor to Kimberly. Its upper-crusty surname feel places it among the new stylish <a href="https://nameberry.com/baby-names/501/english-names-for-girls">English names for girls</a>, successors to Ashley and Whitney.
 Spelled Waverley, this is the title of Sir Walter Scott's popular 1814 novel, whose hero is a young English soldier named Edward Waverley (it's believed that Scott named the novel after the model of pen he used to write it). Spelled the more streamlined way, Waverly is the name of the daughter of Buttercup and Wesley in The Princess Bride and a memorable character in The Joy Luck Club, who was named by her Chinese mother for the San Francisco street on which the family lived.
 Waverly Place in Greenwich Village was named for the Scott novel in 1833--dropping the second 'e', and was the setting of the teen show The Wizards of Waverly Place, as well as Don Draper's bachelor pad in Mad Men, as well as a character on Friday Night Lights.