Of course, as she is loaning it to Lan there is no requirement to wipe it, as babowa pointed out:
“Licensor grants to you a nontransferable license to use the Licensed Application on any Apple-branded products that you own or control. “ As Lan said, Lan’s sister still owns the iPad: “she has purchased many apps, now, i'm using her iPad” (Note: it is her ipad, she owns it, and loaned to her brother.)
You can loan your ipad and let somebody use it as long as you still own it or control it. Isn't that in the agreement? Why do you say: "it is still violating the licensing agreement to try to use someone else's apps." ??? When in fact: “Licensor grants to you a nontransferable license to use the Licensed Application on any Apple-branded products that you own or control. “ please don't spread mis-information.
Do you really think if somebody writes a letter on my computer I should wipe all the apps before I let them use my keyboard?
As long as I own or control the computer I can let someone use it and the apps.
If I sell the device, however, I should clear it.