This woman just lost her ENTIRE support system in one fell swoop. And it was replaced with a bitch like Mahi and her mother. Let's not forget Adi who's sole mission seems to be to torment Zo. It would be unrealistic if Z wasn't crying all the damn time. Honestly, it is annoying to a viewer but pretty realistic.
Also, ppl forget that there are different kinds of People. Someone can cry a lot and still be strong. Some people are not good at confrontations but if it really comes down to it they would fight for what they want. I mean zo might look all chill but let's not forget she fought with her dad to marry Yash and fought again to stay in Mumbai and look after yashs company. Not all of us can be oh so bubbly and effervescent. This doesn't make her good or bad, just human. Z is far more emotionally stable than Adi.