I obviously voted for Ellie...but I believe in Grown up names~that's where it gets tough for us. Ellie as the nickname but for a proper name? I don't like Eleanor, Elin/Ellen....someone on another site suggested an L first name and an E middle name .....LE. Lillian Elisabeth? Interesting.
My reasons for the proper name are that I have two girlfriends named Molly who went into business HATING having dolly/little girl names. One ended up using her mother's maiden name as her name in Business. Something to think about.