What may be the reasons😕?
1. May be Ashgun blackmailed her innocent mind about her papa or Ishita. And thus, Ruhi thought if she stays with her fake mother, her papa will remain happy.
2. May be they said to her that neither her papa nor Ishita aunty loves her; They were just trying to keep her away from her mother (Shagun with crocodile tears)😡!
3. They were successful in manipulating her (We have seen it from the last two episodes by trying fake to make her happy)
4. May be they made her understand that Ashgun place is best for her and Shagun loves her the most.
These are my thoughts. What's yours😉?