when i said he's missing the stone, i meant the one that he has on in this show is clearly just cosmetic. it's not the actual stone.
my thoughts on her telling her kids she can't fix EVERYTHING is that she was being honest, and she knew that from experience. she tried to bring back vision but it didn't work, she brought back something else and called it vision. when vision first shows up, the avengers think he's some amalgamation of jarvis, ultron and the stone, but that's not really accurate. there's no "part" of him that is jarvis, no "part" that's ultron, etc. he is a fully separate entity.
my thought is that wanda tried to bring back "Vision" without the stone, but there isn't a part of vision that exists withOUT the stone. it ends up making him a separate entity that LOOKS like vision, and even THINKS he's vision, but it's not. wanda knows he's different, he's close, but he's not vision. her whole speech to her kids about the responsibility of taking care of a living thing was DIRECTLY because of everything she has to do to keep vision functioning AS vision. there's a part of her that knows it's a bad idea and a terrible risk, but she can't help it, she's in love. the same way she trails off talking about all the responsibilities while petting the dog