How to upload photos saved on a chrome book (G+?) to SnapFish / online something or other

Hi all,

My parents have bought a Chrome book as it was the best low price option for them as mainly simple web browser type users. I didn't even have to suggest it, my Dad ordered it entirely off his own back.

Anyway, I get the standard family support call. They have moved files from my Mum's camera onto the Chromebook. (I don't know whether this defaults to drive or to G+ or somewhere else). What they now want is to upload those onto SnapFish so they can get them printed, however when they go to the SnapFish website, the photos can't be seen in whatever file viewer that pops up.

Now, I live about 150 miles away from home so can't have a look, and don't own a Chromebook myself, so need some help figuring out what next.

1) I assume the photos are uploaded to G+ or Drive. Is there a place that a file picker can see the photos?

2) if they have to be redownloaded somewhere, is there a preferred place that will be best for using as a location for uploading to a website?

3) Can they get around it by plugging in the camera or the sd card from the camera and will the files just show up then as an additional drive?

Thanks in advance!