If she's up to the challenge, the Gainford book "Designs for Knitting Kilt Hose" (available from Amazon) has many traditional cuff designs that can be mated to any leg pattern you like. It's not a pattern book per se but great for the experienced knitter (or over-eager amateurs such as yours truly LOL).

Full patterns available for free online include the popular Toirneach -- I've used this leg with Gainford cuffs to nice effect.

And if she's an online type, there's a group at Ravelry.com where many of the knitting XMarkers and others discuss kilt hose creation, bounce ideas of each other, etc. Not sure how to post a link to it (without signing in to my account) but if she's interested let us know and we'll help her find it.

Wish her luck and let her know there are lots of other people knitting kilt hose to talk to!