Ealhwynn

Based on shortenings of other forms of Ealhswith (where it has been shortened to "Elswith") and endings of other Old English feminine names ending in -wynn (like -wyn, -wynne, -wen, -wena and -wenna), I imagine that Elwynn, Elwyn, Elwynne, Elwen, Elwena and Elwenna could work as other forms. Unfortunately I can't find sources showing these though.