Likely a combination of May and Brie
Maybrie is a modern American invention, likely created by blending the month name May with the suffix -brie, as seen in names like Aubrey or Brielle. May refers to the month or the hawthorn flower, while Brie is often associated with the French region or the name Brianna, meaning high or noble.
US births per 5-year period, 1990–present (SSA data).