no source

The Minhag women have when lighting Shabbos candles to wave their hands over the candles 3 times, has no מקור. (source) There is no mention of it anywhere*. The only reason to do so is because of אל תטוש תורת אמך ראשונים ואחרונים* There is also no mention in Shulchan Aruch for women to place their hands on their faces to cover their eyes. It says to place  the hands in front of the candles to block the light from the candles Perhaps when lighting many candles it's more practical to cover the eyes to solve the עובר לעשייתן (Can be done by simply closing the eyes. No need for hands. Here again, אל תטוש תורת אמך)