Is the ghusl valid, or must it be repeated, if a woman doubts whether she washed her ear or not after completing the ghusl, given that water enters her ear while washing her hair with the shower?

If the ritual bath (ghusl) is for major impurity (janabah), then it must be performed with pure, unadulterated water, and water mixed with soap is not sufficient. One can wash the body with pure water first, and then cleanse it with water and soap. As for not touching the ear while water reaches it, this does not invalidate the ghusl, because rubbing (dalk) is not obligatory in it. One must stay away from obsessive thoughts (waswas), as they are from Satan.