This is the purple shirt that Eve is wearing in the Season 6 episode "Blind Love" (6.07). The label inside says "Eve 1/2" (that is the way production identified their items - 1 out of 2). Since it is the first of two identical items, I am fairly confident this is the one seen in picture 3 (thanks to screencapped.net!). I also found out that depending on the lightning, it also looks like the shirt she is wearing in episode 6.09 "Tree People" (pics 4 and 5). So maybe it was used in both, who knows?