First, your 12 year old needs to start to be given more freedom. Along with that, comes more responsibility. Feed it to her a little bit at a time, see how she does, and adjust as necessary. Start now, or face out and out rebellion as she gets older and her friends have more and more freedom and she has…none. You talk, talk, talk to her about all the choices she is going to have to make, and you allow her to make mistakes NOW while the consequences are not so dire as they will be later on. I know it’s hard to see them grow up, but you are now on the fast track to your daughter’s departure for college in just 5 or 6 years! Start teaching her to make good decisions and how to recover from mistakes now! you have no time to waste. Let her try some things while she is still under your roof. You can discuss as you go along, what is working, what is not, etc. It is harder to do this, but you need to move into a coach mode with her. Your husband needs to be on the same page too. So you need to soften your stance toward methods of communication. I would get her a phone, and I would consider letting her make a FB page, with a lot of controls on it.
I take it all your kids are in public school? Just know that they are going to be the freaks in their classes…It is the coin of the realm to at least have a cell phone and be able to send/receive texts. Actually the voice part of the phone is useless any more, and your demanding that your kids call their friends is akin to making them call in person with calling cards in hand (like in the Victorian era). They may not be fighting you right now, but you can be sure they are feeling left out…(at least the 12 year old).
This thing you have about texting “lingo.” You’re gonna have to let that one go.

I’m an English major and chat room text used to drive me NUTS. now i cn write in lwr case just lik ne1 else. I mean, you have SO MANY battles ahead of you if you are going to freak out because kids don’t spell while texting. It’s actually adaptive of the little dears - it takes too darn long to spell everything out!!
Controlling every aspect of the way kids communicate with their friends is gonna drive you KOO KOO because even as I type this, the next innovation is coming down the line. If you want to continue to deprive them of the manner of communication that most of their peers are using, then yes, take them out of public school and homeschool them. A lot of home schooling parents are a lot stricter about the use of technology.
And I have not always been this sanguine about computers/phones/video games etc. I was quite tech-averse for a long time. But you know, you either roll with the world and make the best of it, learn to ride the avalanche, or you get buried by it. I’m gonna surf the avalanche! See you at the bottom.