Combination of Ka- and Shawna (God is gracious)
Kashawna is a modern American invention, likely created by adding the popular 'Ka-' prefix to the name Shawna. Shawna itself is a feminine form of Sean, which is the Irish version of John, ultimately meaning 'God is gracious'.
Less common today
Kashawna isn't in the latest US Top 1000. It last peaked at #6,948 in 1996.
US births per 5-year period, 1990βpresent (SSA data).