I find my bettas, both male a female, get pale dots on their "cheeks" (outter flap thingie to gills) under two conditions: About to get ill, or horny. Whenever my female starts filling up with eggs and getting her "breeding stripes," the spots appear, and usually my males get them when they are constructing bubble nests. However, I've also had a betta display them right before a major illness. But, if your girl is acting fine and if the "dots" look to more be directly on the flesh as a pigment and not as granules, she might just be seeking a boyfriend, not getting Ich. The fact that they are coming and going makes me think its not Ich, but could you send a pic or describe them more thoroughly?