My DD will be going into 6th grade as well. She does have a phone, but guess what? She isn't going to take it to school with her, she doesn;t have a need to.
Her school last year had a 20 minute lockdown. Classrooms were locked, shades were down and the teacher instructed them to be quiet. It was a unruly student who needed to police to be called.
If she does after school activities, I am going to know about it before hand.
If there is a lockdown, I don't want a kid in my DD's class whipping out his/her phone and listening to their parent freak out and freak out their kid and then a chain reaction of freaked out kids do not listen to the teacher.
This "modern" technology is for our lives to be a little easier, but unfortunately, we become too relied upon it, addicted to it. I know parents who let their kids out til 9pm at night roaming the housing development, but they think a cellphne is going to save their kid from getting assaulted or kidnapped. It's just a form of communication, it can't stop a bullet or someone behind you or more likely someone your child knows from assaulting them,etc.
As for the mother in the OP's situation: She has "allowed" her daughter to act that way, not paying attention to something that affects her in the way of getting to know her school because she wants to text. That just isn't acceptable. She needs to watch Willy Wonka and the Chocalate Factory and learn a lesson from the umpa lumpas-lol.