I think riddhima will see smthing ...She may think that ragini's life is in danger...so thats why this decision to call K and tell him everything..
If there is something else...i dont think she would have said "Ragini is alive" to K...this urgently...
She called K ,that doesnot mean she loves him still..let the story progress...mera dimag ko yeh ladki shot maar rhi...but still🙈