more to your question:

The market is in San Telmo area, that area holds a huge sunday market, so big that one can get really lost if you are trying to find a certain vendor. I went there on a Saturday (and Sunday), there was a much samller version on Saturday; it was in a square located near Calle Defensa. Maybe you can have your frined give her a call first. :)

Good luck with this. I really like this bag, it is ten times cheaper than designer bags, yet it is so unique, currently my fav of all the bags I have.