I'm certainly no expert, but here's what I've seen some designers do in the stores I sell at....
Your friend can design a kit for Personal Use and sell it for, say, $4.00. Now, is she wants to sell the same kit, but for Commercial Use she would just price it a couple of dollars higher. She would have to include a CU TOU which would state that the kit could not be distributed as a whole. For instance...whoever buys it can't then just make copies of the CD she puts it on and sell it as is. Her Commercial Use terms should outline what the buyer can use it for - typically for print projects, like card making, Scrap 4 Hire, Designer Resources, etc. Even though they are buying the kit, she would still retain copyright.
Now...she can also sell a "Commercial Use License" for a one time fee to cover a set amount of kits (or an annual fee). She will still retain copyright and will have to include in her TOU what the designs can be used for. I've seen these fees range anywhere from $20 to $100!

Oops, ran out of space! If the small businesses you mentioned are looking to buy a kit with a view to repackaging it and selling it on CD, then she will have to either charge them a reasonable fee to buy the copyright (which means they now own it and she can't go on to sell it online)...or she could come to some sort of arrangement on earning a royalty fee on every CD they sell.
Just some thoughts...but I hope they help!