Hi,
Unfortunately it is highly unlikely that you can tame these birds. When you put two birds in the same cage, they will almost always bond and then lose interest in being tame. You tame a bird so that it has a companion. Budgies do not have several companions in the wild. Once they have bonded with a mate, they stop having close interaction with other flock members. Even when both birds are the same sex, in captivity they can form as strong of a bond as if they were a breeding pair. The only way to maybe tame her again would be to separate the birds, and that wouldn’t be fair to the other bird. It would grieve just as if the mate had died. And as long as both birds are in the same house, they will just call to each other. The best thing to do is let these two birds enjoy each other’s company. If you want a bird you can handle, I would recommend getting another bird and do not allow it to interact with these two.
Thank you for asking Lafeber,
Brenda