If she sells it to a buyer who initially saw it on Ebay and Ebay finds out, she could be reported and then suspended. Ebay has strict rules about this. Off ebay transactions are considered fee avoidance. (when you've previously listed it, of course)
But if she didn't bid in the auction and contacted the seller after the auction is over, then eBay has no jurisdiction on the sale.
Fee avoidance is more like selling the item for $2 but charging $100 shipping. The actual cost of the item was $95 + $7 shipping. THIS is fee avoidance.
The OP's auction was over when she was contacted about the item, so in her case it is not fee avoidance.
Here are some examples:
Circumventing Fees