While you didn’t say specifically, I presume you have arrived the day before they are leaving for their trip so my answer is based on that…
Spending time in the home while the hosts are there definitely has a weird vibe to it no matter how well you get on, how easy going they are,etc… It always feels better once they depart and you are on your own.
I doubt she was intentionally not respecting your privacy or being rude. And I think giving people the benefit of the doubt–unless we have solid proof otherwise-- is always helpful since the core of our upset is usually assuming they were deliberately disregarding our feelings, making us uncomfortable,etc…
If it were me, I would just let it go rather than saying something to her, though of course this is just my opinion. And the reason I say this is because in this instance you are dealing with a very temporary issue–she will be leaving soon and that will be the end of it.
It wouldn’t be worth it to me personally to create a potentially awkward situation. It is not like you are moving in there as a roommate and you must act to head off a potentially long-term problem.
While it is understandable to not want to spend a load of time socializing with the hosts, nor is it necessary, it is not unreasonable for them to want to chat with you a bit and get to know you.
If your preference is to spend the bulk of your time by yourself–minus any time they spend showing you the ropes–you might want to consider sits where you are not required to stay overnight, or opt for a nearby hotel instead if it is necessary to meet the day before–though you should expect to pay since you are choosing not to take up their offer of staying in the home.
In my experience, hosts don’t expect to spend every second with you until they leave, but a sitter who seemed like they were completely disinterested in interacting with them might not give a great impression.
This is one aspect of sitting that can be challenging for people and it is okay to feel how you feel about what happened; but again, in the big picture, it is one of the smaller potential hiccups you may encounter while sitting since they will be gone shortly.
Good luck!