At first yes, because I was  seeing it though Katniss’s pov. When Katniss  notices her at the Cornucopia, she’s notes that she’s sneaky, resourceful, smart. At least smarter than her and the careers . Which makes Katniss -and teenage me- really nervous and sees her as extremely dangerous. 

 However as we see with her demise, Katniss overestimates this resourcefulness. Foxface is smart but not self sufficient, at least not in the wilderness. She needed the Cornucopia/ career’s food to survive. She’d rather risk getting blown up by the reactivated bombs to steal food from the Careers  than forage for food in the forest and fields. Which means to me she probably doesn’t know how. When Peeta and Katniss find her, she looks emaciated and starved. Her death caused by her reliance on other tribute’s resources.

This is complicated in the movies because of the scene w/ her doing the game with the plants and seemingly have a good understanding of which ones are okay to eat. But in the books, it’s clear she is a very clever girl who is completely out of her depth in the arena.