Generally, the answer is yes, she can. The only exception is that some designer brands will not allow their products to be resold as new on eBay. From your narrative, however, she would not be prohibited from reselling good from B&M. Happy to discuss further.
Absolutely. The source doesn't matter. If she can get it cheaper locally then she should do so. I hope that helps. Please leave a positive response on the system so that I am credited for my time.