smitha maybe somewhere deep down she feels this but right now she has erected a wall around herself & Chahat & she doesn't anyone, specially Prem to invade that, plain & simple. Its not her love that is making her run but her insecurity as a mom. What if CHAHAT start to hate her for keeping her away from her dad????????????????She doesn't want to lose Chahat, her only anchor in her life, the reason for her to live. Its more for Chahat rather than herself that she is running.
Right now Heer's feeling for Prem is very strong Smitha, love is the last thing she feels right now, she is dejected & disappointed with love, all broken from within with no hope whatsoever! She can't ever trust or believe Prem & thus wants to be away from him as far as possible. Its pure simple logic, right now love is not for what she is running, she loved once with the picture she has of Prem not the Prem who she thinks slept with Ash.