There are no details of what she does with the info, so sounds like magic to me. Either she's naturally really good at classroom management, and this is her unique tool, or she should immediately quit and right a detailed manual/book outlining her methods so that others can implement them.
i have done similarly for several years as a teacher: by making "chavrusa" learning for 30 min a day with weekly/monthly changes to include the less-popular students learning with the more popular students. This increases the less-popular student's self esteem, and it also reinforces practice by the more popular students to include and to be aware of all peers -- even if they are not usually friends during other classes.