Yes, separate them for now, just put the cages near each other so they can still communicate with each other. Not having a mirror is nonsense, it is one of the best ways to tame your budgie. I have owned many budgies over the years and they all had a mirror. I found they would get attached to the mirror and when I took it out, they would lose all fear and come out to me because they wanted to be near the mirror so much. After they got used to being on me with the mirror I would put it away and the budgie wouldn't care so much about it because they got interested in other things and would explore and play with other stuff. I always put the mirror back in the cage with them. It is a great training tool.

(Long story) i use to have a girl budge but i wanted her to reproduce so i bought a boy budgie and i would always see the girl kissing him and getting close to him and he wouldnt like it and one day we found her dead in the cage so time passed and i bought another girl and she defends herself but they fight a lot and i went to the store and asked the lady and she said i should put another girl in so they wont fight so i bought another girl and they didnt really like her and we found her dead in the cage , are my budgies safe inside the cage together ? Should i seperate them? Also i wanted to tame them but my boy bird has a mirror and i didnt know they shouldnt have mirrors but if i take the mirror out can i tame them? Thank you for your help!