The name Bessie is a girl's name of Hebrew origin meaning "pledged to God". Bessie and is often added to lists like Nicknames for Elizabeth and discussed in our forums with posts like "How many ____s do you know?".
From the experts:
After a century of association with horses and cows, this name just could be ready for revival by a fearless baby namer -- after all, it did happen to Jessie and Becky.
Bessie has been in use since the seventeenth century and is found as characters in Jane Eyre and in Sean O'Casey's play The Plough and the Stars. More recently, she was an animated automotive character in the movie Cars.
On the popularity lists until 1975, Bessie was a Top 25 name from 1880 to 1906, reaching Number 9 in 1889. Notable namesakes include the great blues singer Bessie Smith, and Bessie Coleman, the first African-American female aviator.
And if you want to go more refined, you could simplify to Bess.