Your nine year old is old enough to take responsability for her own toilet needs whatever happened to the old method of reminding her to go to the toilet there are toilets on the plane you know! in fact im positive there are because i Know I used the toilet on the plane traveling to spain from britain and back only over christmas and new year! !secondly reminding your child to go to the toilet !yes I know its tedious and gets monotonous but we are parents and if we werent prepaired to do these things for our children then why have these precious little ones!. ok well not so little but why pack diapers and plastic pants and take up all that extra room when she can use the Toilet/Bathroom etc; after all it isnt always she has accidents! as you say Maybe 3 times a week well in a week there are 168 hours in a week and you your self said maybe 3 times per week denoting an air of uncertainty so if it was contstant then yes i would say look for any physical problems then consider nappies and pants only as a very last resort!. hope this is of help to you best wishes, TOM