I'd fully expect her to be nervous. It is always hard for soloists that began in girl groups to being promoting alone. Taeyeon, Chungha, Sunmi, and others often comment on how odd it feels promoting alone after they had been in a group even years after they have gone solo. Even if you had some individual activities back when you were in a group you had members that maybe wished you good luck in person before you left, maybe went with you as they didn't have a schedule that day and figured they would keep you company, or were there at the dorm when you got back and were interested in hearing about your day or had waited up to order something to eat with you as they suspected you might be hungry and not want to eat alone. Also, when you go on music shows or on the radio you are used to having the other members there supporting each other and the group mood makers keeping spirits high. Now it is pretty much you and some staff members sitting around and it isn't quite the same even if you are pretty friendly with them. She'll get somewhat used to it eventually, but especially with this first promotion it is going to feel real empty backstage in the waiting area. At least on Music Core and Inkigayo she will see some familiar faces backstage a little, which will be nice.

Thanks for sharing, I am very impressed with your post.