First, I'd get them their own cages. Throwing two birds together is like someone shoving a random person into your room and expecting you to just start living with them. Not fair and very uncomfortable. Secondly, I'd get rid of the mirrors. That can cause a lot of fights because they can view the mirrors as their mates and the other bird as a threat. Bonding takes time and they may never be the best of friends. Definitely do lots of out of cage time with them so that they can get used to each other more slowly.