That would be my first thought since it would probably be the highest chance of getting along with Ona. Idk though I'm interested in other Conures too. However Ona is a tiny girl still, only 62 grams, and I would be nervous about getting a Conure too much larger than her for safety reasons. I'm not going to lie I've still been thinking about that poor Turquoise GCC with half a missing tail I saw at PetsMart....
If I DID get another though it would probably be safer to get one from the same place I got Ona so I could visit it as it grew just like I did with her.
The thing is, if I knew Ona would enjoy another bird I would do it in a heartbeat. But right now she lives a very spoiled, privileged life and spends most of her time out of the cage with/on me. I would hate to be in a situation where that is ruined for her if she didn't get along with another. I do think she shows some good signs of being interested in other birds. When she sees or hears my backyard birds outside she gets very excited and seems interested. She doesn't mind me playing videos of other birds for her to see or hear. I just don't know. I've also though about trying to foster a bird so I can see how she would react. But that is harder to come by.