Della

• Same eraMavisLike Della, it was given most in the 1920s.#560 · rising
• Same rhythmMargoSame beat as Della: two syllables, stress on the first, ending on a vowel sound, but it starts differently.#559 · rising
• ShorterSkyeOne syllable to Della's two, so you can tell them apart when you call both.#529 · steady
• LongerArmaniThree syllables to Della's two: a long name beside a short one keeps them distinct.#562 · steady
• RiskyIsabellaRhymes with Della. Cute on a birth announcement, confusing across a playground.#7 · steady

Suggestions come from names in this year's top 1,000. Rhythm and rhyme are judged from each name's pronunciation (Wiktionary's, or espeak's reading of the spelling), so a few calls may be off.