Most of the stuff I'd recommend (wireless headphones, books especially if there is a new one out from one of her favorite authors, board games) are things that have already been recommended by others in this thread. So the only other (Non gaming) recommendations I could make is get her a record player (if you don't already have one) along with some albums from her favorite bands/musicians/music genres (this could also be something down the line that she could use to help soothe/calm/entertain the baby after they are born) or if your not to keen on a record player how about one of those portable iPhone speaker docks/Bluetooth speakers if you don't already have one.
Now if you are absolutely hell bent (and I do mean HELL BENT) on getting her something gaming related then I'd recommend going for a custom controller for her or go for games such as the Tomb Raider reboot games (or the Tomb Raider Trilogy on PS3 if she's not too keen on the reboot series), Atari Game Collection (there are currently 2 volumes for both PS4 & Xbox One)/ Namco Museum Remix (this is on PS3 if irc)/Tetris Ultimate (PS4)/any retro game collection, Pushmo/Crashmo/Stretchmo games (3DS), Super Princess Peach (DS, recommending this cause 3DS can play DS games), The Pheonix Wright/Professor Layton games (DS/3DS), Hey Pikmin (3DS), Kirby Triple Deluxe (3DS), Life is Strange (the first one, not Before the Storm), Splatoon 2, the Crash Bandicoot N. Sane Trilogy (PS4), Titanfall 2 (would recommend the Destiny series since she use to be into Halo and it's made by Bungie the studio behind the first 3 Halo games, but those games are loaded with micro-transactions & loot boxes and that imo is a rabbit hole you don't want to go down into), or Mario Kart 8 deluxe.