Pondering a Microsoft Surface tablet for my mom. Can I load e-books on it? [View all]

She currently has an old Kindle, which, if I read correctly, will soon be obsolete/unusable as 3G networks are phased out. I want to upgrade her before that happens, because reading is just about all she can do anymore given her health issues. So I want to be sure I'm getting her something she can use. with her fading eyesight, she needs L-A-R-G-E PRINT, so I want something that can enlarge the font of the book she's reading.

Does anybody here have any insight on these? Would appreciate.