Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
Based on Snow's history prior to the trip and her signs while you are away, this is highly suspicious of feline stress. Often our cats struggle with any life change. So, if you have been her main companion and she is quite a nervy cat already, then her reactions are not unexpected.
Now if your being home is settling her, that may be all that is needed. That said, if she is still quite unnerved or you do have any travel plans in the future, it would be worth considering the use of some de-stressing tools to help provide a general peaceful environment for her. Often we will use Feliway, (also known as Comfort Zone in the pet stores) which is a synthetic cat pheromone that helps to relieve stress. This can be used as a spray or a plug-in diffuser. There is also a diet on the market called Calm by Royal Canin. This contains a number of supplements that have been found to provide stress relief to cats. As well,there are nutritional supplements like Zylkene and Kalmaid to soothe anxious cats that could also be used here to help her cope with this stress when you are away. And as they are not drugs per say, they can be used together as needed.
Overall, based on what you have told me about Snow and these signs while you are away, this does raise suspicions of a feline stress situation likely related to your absence. If she is settling now that you are back, this may be all she needs. Of course, if she is still unsettled or before any future trips, the above should be considered to help keep her calm and help her to cope.
Please take care,