10 months later:
Celestia was thinking of how Luna's progress was coming and she could say there has been some progress at the very least.
Celestia kept her ban on Luna's duties for a month when she was sure that Luna's mind wasn't self destructive (she did kept one solar guard to inform her if things looked bad), she was proud and relieved of her for that but knew that this was only the first step in the long road to recovery.
Celestia was still feeling some shame on herself because of her inability to see Luna's suffering again but knew that meant that these "sessions" were also helping her to know how to be a better sister.
Not only they talked about Luna on their reunions but also of Celestia, how was her day, duties, her students, the reign for a millenia. All things that Celestia was never able to talk truly and without having to curb what she had to say if it was somepony else, with Luna she could be 100% truthful and be accepted, it also helped Luna to see that Celestia wasn't as happy as she appeared to be.
Thinking back she still felt some shame for snapping at Luna like that 10 months ago, after 1000 of being in control and ahead of any problems, the fact she would have been sleeping unaware when something like the Tantabus happened was a buck in the jaw.
Still was no excuse to lose control like that, even if it was something she subconsciously thought wouldn't happen until her retirement.
Celestia really should have thought of making these reunions before, earlier than Luna's banishment for sure, but she was always so busy than she thought she couldn't take a break if that meant that some ponies wouldn't have the chance to pose their problems to her.
It was only until she started to take personal students that she discovered she could take breaks from duty without ponies in need being ignored, it just took some better time management wiched worked thanks to her assistants.
She knew now that it was stupid to think she needed to listen to as much ponies as possible but at the time considering the world was a more dark place she thought it neccesary. Even so it wasn't that bad, ponies were mostly content aside from attacks at night which were handled by Luna and a lot of requests were for small things.
In the end she was probably too kind, she gave so much to the ponies, even those that didn't need it that she had nothing left to give to Luna and she paid the price. Kindness can give way to naivete, she learned that the hard way.
Celestia really thought that Luna, while not revered as her, was accepted and appreciated thanks to her efforts. She should have seen the truth, they hated her and everything she represented.
She deluded herself into thinking that it was always the individuals that had trouble with her that made it to Celestia's court and the majority of the population thought good of Luna.
As she was thinking on pony behaviour during her time as sole ruler she discovered that ponies always seem to want to blame something for their sufferings that's not themselves or their group. First it was race on the era of three tribes, then it was Discord that while justified whet way beyond his reign that her subjects blamed Discord for a lot of things, then they blamed the night and Luna and finally today it was other species that while Celestia made efforts to stop them, it was still predominant in a lot of small settlements.
"Twilight will hopefully take care of that when she ascends, as princess of friendship she will surely stop such thinking from my, no her ponies," Celestia thought.
She was completely surprised when she realized how devoted the ponies were to her and the day, she received petitions to make the days last as long as it possible can or even find ways to make plants be able to last in the sun all the time so they could get rid of the night. All rejected of course but still hurt to see the hate they had for the night.
The celebrations, they were so enthusiastic to celebrate the banishment of Luna that she had to compromised and make nightmare night so the ponies could be happy, she didn't want to antagonize them so she could make reforms easier in the future.
It took a lot time to make the reforms as she had to wait until ponies forgot about Luna (how that hurt Celestia to do but it was neccesary) to make them or they'll think that she was doing similar to Nightmare Moon (nonsense but Celestia knew ponies could be easy to panic).
Changing her focus to the present Celestia went with how Luna was progressing. Aside from some moments she had to hold her crying on her she seemed to start to get some confidence back, particularly in the dreamworld helping foals with their nightmares as she not only stops them but talks with the foals about their problems.
It wasn’t the same in the real world for the moment though as she was still pretty shy when dealing with strangers and preferred to stay well away from most public matters.
Celestia gave the idea to Luna that she could support astronomy in the nation, a young and very small field that certainly could use the found of the crown. Luna until now has supported without going herself to meet them but it was unlikely it will stay that way for long. Luna was giddy to help ponies who studied her night and it will eventually override her fear of rejection.
At least when the sisters were alone Luna was voicing her opinion more even when it was something that contradicted Celestia, it was rare sadly but hopefully it will get better soon.
"As much as I have avoided bad decisions in the past, I wonder if there were better options that Luna could have thought of," Celestia thought.
The idea of a physcologist was in the end scrapped as the risk of somepony finding out was too great.
Celestia decided it was to think of stuff as she went on with her day.
It was a long way before Luna resembled the mare she was in the past but Celestia knew it would only be a matter of time for it to happen.