Not really. This should be a strict liability case and it does not require the merchant did it intentionally or knowingly, not even recklessly or negligently.
UCC 4-238:
A limited warranty that goods shall be merchantable is implied in the sales of the goods. Goods to be merchantable must be such as (c) are fit in ordinary purposes in which they are used.
Her contributory negligence is also something needs to be considered.