Chi Enen is not fragile, not in the least; she just appears more gentle on the surface, but her heart is stronger than anyone else's. If she weren't strong, she wouldn't have grown up in such a distorted family and still maintained a kind heart. Nor would she have been able to quickly adjust her mentality when faced with the distressing situations crafted by Chi Ya, Gu Qiaomei, and Chi Jianguo.
She never cursed her fate, nor complained about the society, instead leading a proactive and optimistic life.
It's him who can't bear it, it's him who's afraid!
In this life, he's dedicated himself to one woman only, wishing he could meld her into his chest, bury her deep within his marrow! He'd love to imprison her, to cut off everyone else in her life and make it so that in her world there is only him, only him for her to see!
So the fragile one is him, the one who fears even a gust of wind might strain Chi Enen's back, is also him!