We have tried mirroring too and it can be helpful, but only to a point, which is what I want to warn you about. You two are extremely enmeshed and looking for change in the other to validate yourself. Mirroring can help address some of this need because you can hear that the other person hears what you just said. So there is validation in that process.
I think this is effective for someone who needs WOA or QT as his/her LL. It will not help as much for someone with a PT LL, like CAC. Sure, the mirroring will help to eventually move toward PT, but that might take a while, so CAC could become frustrated by the process and give up.
The other "problem" of mirroring is that it is only intended to make each person feel their needs have been heard. It does nothing to address those needs (unless the need is to be heard). So after a while, mirroring started to sound very hypocritical to me. My wife would repeat what I said, say she understood it and that it makes sense to her, then go about her business just like before. This sabotages the whole process.
Counselors will tell you mirroring is not meant for agreement with the other person's needs, or that one should have to meet or agree to those needs in any way, but only to acknowledge they exists. Without some effort from my wife to show she was willing to actually do something to meet my needs, her mirroring back to do became nothing more than placating. And it only served to piss me off more.
