Unpopular opinion coming through; I went away last July for 5 days, and left my hamsters alone. I fed and watered everyone the day I was leaving. They did perfectly fine; they had plenty of water, food, and whimzees that kept them occupied and I honestly don’t even think they noticed I was gone. I left them two water bowls each, and they was still more than enough left when I came back. It’s not that I wasn’t bothered and couldn’t find anyone to look after them, I couldn’t trust people not to mess with them or close their enclosures properly. If it was any longer, I probably would have just bit the bullet and asked our pet sitter to mind them too… but 4-5 days, to me wasn’t a big deal.
There are certain animals that I wouldn’t leave alone for even just 24 hours; I have 4 buns & a hedgehog, who I *always* have someone check on and tend to if for whatever reason I have to be away for even just a day (because of specific requirements that they couldn’t go more than 24 hours without). Hamsters, honestly, tend to do perfectly fine. I would have trust issues with bottles; they can be temperamental and block up completely or leak everywhere, and would offer bowls instead. Heavy ceramic dishes on a solid platform, and you should be good to go.
A week is a lot, and it’s longer than what I’ve personally done and Just to be clear; I certainly wouldn’t advocate for regularly leaving a hamster completely unattended for 5 days, or a week or whatever it may be. *But* I do think that there are measures you can put in place to ensure that all their needs are met should it ever be required to do so. Is it the ideal situation? Certainly not, and if you could find a pet sitter that would obviously be the preferred option. Although I haven’t gone as long as a week, and perhaps it may depend on your hamsters personality, but I’ve left my guys for 5 days and none of them fretted for a second. Even if you could get someone to watch her for just 1-3 days even, and leave her alone for the remaining 3... providing she's left with enough food and water, i wouldn't fret - personally anyways.
