Hmmmm she is looking like she has something that your other girls need to stay away from hahaha. But no foreal red stems like that is a sign of disease. And the fan leaves falling off too. Those buds look weird, where do you keep your nutrients when they are not being used? A grower on here Intution had a similar experience with the red stems leaves falling off WAY to early in flowering and then sparatically she just died. He did a bunch of research and narrowed it down to him keeping his nutrient bottles in to hot of a climate. I think they saw temps of 100+.

Peace