Is this it?

I think the time was just reset, like their very first meeting started all over again.

so everything just happens again in a loop !?

ah!
maybe that wasn't the first time their met and she forgot it!

What I understood of the last part is that the moment/time that they met happened again, the time returned to that day when they first met her still an "air" but with her memories of their first meeting under the tree and so does the others so the moment she arrived there they are already gathered waiting for her.

If the day they met for example happened November 20, 2015 and the time where they went in the tree was January 27, 2016 after what happened the time returned to November 20, 2015 when they all first met.

so complicated!!!