Hello, i have two budgies, one is Ludwig (blue), and the other one is Gerta (green). I bought Gerta first, but after reading a bit i realized that it would be better if i bought her a friend because i wouldn’t be able to spend enough time with her due to my school and other things. My sister also got a budgie when i did, but it was already sick, and in two days when we realized that something is wrong and were already almost at the vet she sadly died. So when i got my second budgie she decided to get two together and tried to look for friends and be careful to not separate any two best friends. On the website i was reading about bringing a new budgie i didnt read anything about quarantining so i put Ludwig in the cage right away which i now realize wasn’t good on my part, but thankfully they came along well and became friends. The thing is that Gerta was constantly calling my sisters budgies or just one of them, and they would just call each other a few times a day very loudly, while Gerta tried to get out of the cage by any means. So it started looking to me that she wasn’t as much friends with Ludwig, as much with one of my sisters budgies. Now a few days she suddenly started being more aggressive and mean, sometimes pushing Ludwig of the branch, flying to where he is sitting or eating and pushing him away, and then other times they look like good friends again which is confusing. I was already to start working on separating them for a few weeks, but i thought maybe this can have something to do with the relationship between Gerta and one of my sisters budgie, and maybe instead of separating my budgies, i should switch homes for gerta and possibly relocate one of my sisters budgies to my cage. Why this also may be a good idea is because my budgies are different genders and im worried about breeding, but if my sisters budgies are also different genders we can just have boy with boy, and girl with girl. Can this be a good idea or is it too much stress for them? They are not that far from each other so they always hear each other and as i said before sometimes talk, but this is almost never happening now unlike the before. Maybe we can have them all live together in my big cage so they are not separated and dont miss each other possibly? Here are my sisters budgies, i would be very thankful if someone could tell me their age and sex, and also any help and suggestions with the situation im in. Thank you!