Cockatiel company for my budgie?

[Jesterben]

Hello I have a year old female budgie. I am really interested in purchasing a cockatiel. I would keep the cockatiel in a separate cage close to my budgie. I have heard female budgies are pretty aggressive when it comes to other birds is this true? Would my budgie be okay with a cockatiel in a separate cage (I don't want her to be angry with cockatiel through bars)? What gender cockatiel would be best? Thanks for your help