[Atunah]

I don't know which kindle we are talking about as the older models have a bit of a different way of getting to things. But the easiest way would probably to just sort her kindle by recent. On the Paperwhite, Voyage and Oasis and basic kindles, use downloaded on the left drop down. All items on the middle drop down and then on the right dropdown use recent.

This will sort items on the kindle by when they were last opened. So should be towards the top, depending on how many books you opened since she read hers.

Older kindles like say the kindle keyboard. On home page go up with the navigator and make sure it says "by most recent first" on the top right. If not you can put the curser there and go right and select in from the list. The other sort options are title, author and collections.

You can also try just using the back button. It goes back quite a bit. I just tried on my Oasis. On menu just the left arrow. Keep hitting it. You might end up right back in the book. I do not know how far back it goes, but just trying it kept going back to my book after I been all over the place on the device.