New reader for mom

Hi all

I finally convinced my mom to get an ebook reader. I am looking for something really simple for her around 6-7 inches. It does not need to have wifi cause she does not have internet.

I will be loading the books for her so it should have an external SD reader and it should be able to read ePub, mobi and PDF. A backlight for night reading would be good too.

Any suggestions?

Thanks.