False as obviously being by the sea shore there would be no need to buy them. Unless she was some kind of power collecter and had wiped the shore of shells so she could monopolize... in which case still false as no one would buy from someone so greedy and would just wait for her to drown (as she would undoubtedly be overweight with sea shells) at which point the tide would likely refurnish the shore with sea shells for anyone who cared for them to have for free.