Per the next strip, they look like large mittens to me.
Those ARE her mittens. She didn't take them off for doing the cleaning.
Leave it to me...Onee-chan's finger-brushing's made it all smooth...!Bliss...♥
Bliss...♥I Feel Much Better Now...Hoppo will comb out Onee-chan's hair next...Thank you...Well? Is it working? Is it working?Whew... all done...