Widely found in Europe, Hebrew "woman of Magdala", a village on Lake Galilee; NT Gospels.
In the 1841 Census of Aberdeenshire this name occurs with significant frequency; the spelling Magdalene was twice as frequent as Magdalen. There are many variations in the spelling but all should respond to Soundex searching, except the abbreviation Magd.
To some extent Magdalen and Madeline [and their variants] can be interchangeable in some family situations.
A correspondent [JP] notes that her "g-grandmother was born Magdalene [and was] also known as Madeline."
In France and Germany, Magdalene is thought to be the more learned form of Madeleine.