Kristen Stewart at the Sundance Film Festival for 'Welcome to the Rileys'

Yesterday, for Kristen Stewart, the Sundance Film Festival really began.

As the Los Angeles Times put it, "By some strange cosmic fluke, Kristen Stewart portrays a 16-year-old runaway in both of the movies in which she appears at this year’s Sundance Film Festival."

Yesterday, she participated in photo ops for The Runaways and then attended the premiere for Welcome To The Rileys. Today, she'll attend the premiere for The Runaways.

The reviews and buzz on Welcome To The Rileys are very positive, thus far.

For instance, Variety confirmed what has been a floating sentiment for a while now - "With a cast like this, buyers are sure to be interested." They also remarked on Kristen Stewart's performance in the film, saying "Stewart is the perfect wretch, utterly convincing as a lost girl leveraging her sexuality to compensate for her complete powerlessness."

Her performance in the film was also raved about by Hollywood and Fine, who said "Stewart attacks her role with a clarity and ferocity that is compelling. Stewart brings an emotional nakedness and spirit to the role that is reminiscent of certain male actors when they were young: Sean Penn for one, Leonardo DiCaprio for another." The Hollywood Reporter said that Stewart's was one of three "nice performances" in the picture (co-stars James Gandolfini and Melissa Leo being, of course, the other two).

During press for WTTR, Stewart spoke with E! Online and recounted her preparation for the role. "[I]n preparing for the role I talked to a lot of people, actually like three people in New Orleans, that were strippers that were working in this bar that we ended up using in the movie," she said. "[My character] literally walks around with an open sore."

As USA Today explained, "her character is so obviously wounded, both emotionally and physically, judging by the many bruises on her body, that it quickly becomes awful instead of enticing." "For an actress like Stewart, it would be easy to play it safe. Knock out a romantic comedy or a Nicholas Sparks weepie while the vampire cash keeps rolling in from Twilight sequels. Instead, Stewart is challenging herself, and moviegoers, too."

MTV goes on to say "Kristen Stewart is utterly fearless in "Welcome to the Rileys." You can quibble all you want with her portrayal of a 16-year-old runaway turned stripper and prostitute. But you cannot walk away from a viewing and say the actress doesn't fearlessly expose herself physically and emotionally, and doesn't do so with astonishing maturity and believability."

Sundance, we're not in Forks anymore . . .

After a day of business, Stewart and her The Runaways co-star Dakota Fanning took to the stage in support of - and to join - their friends (and characters in the film) Joan Jett and Cherie Currie during the concert Joan Jett & The Blackhearts had in Park City.

Much, much more from yesterday is available Here