Taming older budgies is the same as taming the younger ones so since you are aware of the stickies in the Taming and Bonding Section, you'll know how to follow those and work with Sid and Stella.
With regard to Celeste, I'd just recommend that you simply try to spend time next to her cage every day on a regular basis. Even if she makes her "irritated" noise at you, stay there and calmly sing, talk or read to her. Over time, she'll become re accustomed to your presence and will be more accepting toward you again. When that happens you can start over with the taming by placing your hand on the outside of the cage when you are spending time with her and then progress slowly to inside the cage, etc. -- just as you did before.
Good luck and best wishes!