I'm very sorry to hear of your budgie boy's passing...
You have my deepest sympathies.
Rest in peace, handsome Fluffy.
You mentioned on your other thread that his mate has been bullying him, and this was most likely due to the fact that he was sick.
If I were you, before even considering getting a new budgie, I would take your female at the avian vet's for a full check up. If your Fluffy's disease was contagious and since your female was in contact with him, there is the chance that she may also be sick.
The fact that she turned against her mate during his time of need makes me believe she will not be as receptive to the prospect of getting a new friend.
If you do turn out by getting her a friend, you should be aware for potential problems and to separate them in case they don't get along.
Also the new bird needs to be quarantined on a different cage and room away from your female. This is done as a safety measure to prevent any possible illness to be spread between them.