I second the toggle bolts/mollys. The best thing we have found is the Toggler by Snaptoggle (here is a link to a similar product on amazon) They are super-easy and tote that they are twice as strong as regular toggle bolts. Haven't had any problems with them.
Does she want to lie things flat to dry or hang them up? If she just needs something to hang the clothes on, maybe a slide-out valet rod would do the trick? Could probably DIY something that would attach to side of existing cabinet and push back in when not in use. The ladder/pull down idea...
Here to link up to some like-minded garage lovin' folks. We create some pretty stellar garages and are always on the hunt for new ideas. Not here to self-promote and hope to use this board as a resource for helping us become a better company by listening and helping out where we can.