Major Problem With Inception?

Cobb's wife, Mal, loses sight between what's real and what's reality after waking up from her 50-year long dream. She ends up killing herself thinking she will wake up in the "real real world". If this really does happen (she wakes up in the "real real world"), Cobb should be asleep next to her. All she would have to is give him "the kick" to wake him up to her "real real" world, and they'd live happily ever after. This isn't the case, so the ending doesn't seem to be able to go both ways. Can someone please explain this?