Moving house is very stressful for chickens as they have to get used to different surroundings and maybe different food, as well as re-negotiating their social order. I'm glad she's better today, but keep an eye on her because if she's under the weather a bit, the others are more likely to pick on her and make things worse. check she's eating and drinking OK, and if not, give her a bit of time and space on her own to rest, eat and drink, in the shade. Yes, sun is good, as long as they always have shade when they want it - chickens usually prefer shade and you must be sure they get the option of it all day, as the sunlight moves round, so they never overheat.