The wiping of the woman over her khimaar is based upon the man wiping over the Imaamah (turban). As wiping over the Imaamah is stated in Bukhaari and Muslim, There is some difference about the narrations from what I have read. But it seems that wiping over the khimaar is permissible in shaa Allaah and Allaah knows best.
أبو سلمان النمري طلحة بن وليم
والعصر ان الانسان لفي خسر الا الذين آمنواو عملوا الصالحات و تواصوا بالحق و تواصوا بالصبر