It sounds like the old advice, "If your friends jump off the bridge would you?".
I would sit down with her and give her all the information that you can find. There's a lot of info regarding to surgery, recovery, activations and training on this forum.
Even though you are the one that can make the choices, but I would leave it up to your daughter. She has to understand that CI is not something to have because it's "cool". She needs to understand that things will sound terrible at first, and she doesn't just go through surgery and activation and be done with it. She will need to go back to audiologists for mapping sessions. If she is just getting it just because it's "cool", then she will more likely not use it in the future when she gets older. It's not a temporary decision, it's permanent.
I know it may sound like the doctor says she ought to have the CI now...do NOT listen to that. It doesn't matter what age someone has the CI...what matters is the maturity and the ability to go through training and all that stuff that comes with having a CI. Take your time to do research, and don't allow the audiologists or doctors pressure you for anything.
Most insurance companies will pay for one, few will pay for both.
There are three cochlear implant companies: Cochlear, Med-El, and Advance Bionics. The oldest is Cochlear, 20 years. Their internal processor hasn't really changed that much, and it still has 22 electrodes like it did 20 years ago, and I don't perceive that it will change any more, maybe smaller, but most likely the same. AB is fairly new, and they have changed the internal processor to the point where their first processor is not backward compatible to the newest external technology. Hopefully, AB will make sure the internal components will be backward compatible for future processors.
I'm not too familiar with Med-El as it's not common here in the States.
Having said that, technology is very similar to what it was 20 years ago, so it didn't really change that much...only the external processors. Cochlear has had Freedom processor for years because there's really not that much to improve on...it pretty much has been perfected (although, they could change the design a little to make it less bulky).
If she can hear very well with her aided ear, she probably will do well with bimodal approach. Since her ear has not been simulated with sound, having a CI is very different because there's a lot of factors in having bilateral "hearing". CI will sound terrible at first because her ear hasn't been simulated, but should get better over time with training.
Don't be afraid to ask us a bunch of questions and stuff. Majority of us have been there with making the decisions and stuff. Take your time to make sure you have the informed decision and share everything with your daughter...after all, it is her ear. If she keep insisting it's because she wants to be cool due to her friends, I would hold everything off until she's mature enough to understand that just because her friends does the stuff or have the stuff doesn't mean that she has to please them.
Hope I gave you some insight. BTW - I have NO kids whatsoever, so I have no idea what it's like to really parent a 12 year old....but I do find the more involved the kid is in making any decision, the better she/he is.
Hugs!