No, this word is definitely insulting in its original meaning.Shiksa - A non Jewish woman. not insulting usually used if she has a Jewish boyfriend, and who usually ended up as in-laws.
it is derived from the Hebrew "shiqquts", which is usually translated as "abomination". That word is used to denote something that in Judaism is hateful to God, or totally contrary to the law of God.
The verbal form of "shiqquts" is "shiqqets", which means literally "he acted in an abominable/hateful way". That verbal form is the origin of the Yiddish word "sheygets", as insulting description of a male Gentile.
The feminine form of "shiqqets" is "shiqqetsah", which gives the Yiddish word "shiksa".
The use of the words "sheygets" and "shiksa" to denote Gentile males and females respectively has its origin in the traditional medieval Jewish view that Gentiles were abominable people, hateful to and rejected by God. Perhaps those words have now lost some of their original religious meaning, but they are still basically insulting.