what could have happened

she saw zakir through the window doing some tough excercise

she was keenly observing him

does that have any connection for sandy to withdraw from her decision

i strongly feel 

she will  decide  not to chop

but how did she change her mind

what made her do so

not able to view any links as all are blocked 

couldnt watch that zakir practising properly

she needs to prove she can do any sort of tough acts inspite of her long hair

That might have made her change the decision. I mean she needs to be herself that's it and prove it too. 

Sandhya was not watching Zakir but the rope that he was performing with and haircutter's dialogue source is somewhere and treatment is done elsewhere, so she might have realized her long hair is not an issue but loose hair😆 so she can braid it and it won't be an issue then.

akka what an explanation

Me too feel the barbers dialog is the key. He says the problem is somewhere n the treatment is for something else. So watching Zakirs determination n focus, his zeal n will to axcomplish, she will realize that her hair is not whats causing her problems but her lack of focus, n halfhearted attempts. So she will get over her distraction, n pining for suraj, RP, n start focussing on her task with renewed determination! 

So don't think any hair cuts!