Queen Elizabeth has held the nickname Lilibet since she was a child. It came about as a result of how the then-princess mispronounced her own name as a young girl. Lilibet originates from the Hebrew name Elisheba, which means “God is my oath.” Origin: The name Lilibet is derived from the biblical name Elisheba.
https://www.verywellfamily.com/lilibet-name-meaning-origin-popularity-5188529

