The only way to see Ari is through her meet-and-greet pick up. Thats your only chance to ask ari for a gun.
okay let me explain my process. start new game, do sammy poppi first, then i make sammy happy at first but then upset, then i make poppi happy and i dont get fucked after breaking the bot with the screwdriver, then paper on bed says ask poppi for a gun, did that now it said ask ari for a gun. did ari and maddie date but soon it ends up to me ending up forced to shoot the guy, so i pretty much didnt ask ari for a gun, and i looked in files and stuff and found some images like maddie pissed off, ari holding gun, and ari holding alcohol.