Shulamite and Shunamite seem to be used interchangeably in Tanach when describing certain Na'arah women. For example, in the story of Elisha, David in his old age( with Abishag) and in the Song of Songs. Are the "lamed" and the "nun" telling us something I need to understand?
The letters ד ת ט ל נ are all related. They are known to some as "dentals" because these sounds rely on very much on teeth.
See Ramban Genesis 25,3 who states explicitly that lamed and nun are often interchanged.