Yes, please start with Etsy or Ebay.
She needs to formulate her business plan and get a good idea of what her startup costs would be if she wants an independent site: What will be her hosting costs? Can she build and maintain her own site or will she have to hire someone to help her? How is she going to attract people to her site (ad $$ and search optimization)? Is she going to sell her own stuff or sell for others? How will she maintain inventory? et. etc. etc.
Do not quit your job. Running a business, whether on line or real, is a lot of work and expense.