It can actually be difficult to find literary criticism on the Internet, and your first best resource for literary criticism is always the library, particularly a local college or university library; even a city college will suffice. However, a few articles on literary criticism can be found on eNotes. But, there are not any articles that specifically address Juliet's characterization. While that's true, we can infer a few things about literary critics' views of her characterization based on some of their arguments.
Clifford Leech speaks of Juliet maturing. He argues that her language shows both how inexperienced she is and also how she matures throughout the play. An eNotes article refers to his work, but does not aptly show his argument, so you'll need to access his full essay, which is cited as being found in E. C. Pettet's article "The Imagery of 'Romeo and Juliet'" in Vol. VIII, No. 45 of the journal English, pp. 121-126 (eNotes).
In addition, while Leonora Leet Brodwin's argument is more about how Romeo and Juliet relates to Courtly love, she also refers to Juliet's growth by pointing out that, persuaded by her mother to think of marriage, she begins to "look at men differently" that night at the ball. Brodwin further refers to Juliet's growth by arguing that accepting falling in love with Romeo at first sight was also a submission to her own fate (eNotes).
As Juliet's growth is a huge part of her characterization, we can see that both of these literary critics hold the view that she did indeed grow as a character.