Yes ,I agree with all of you , that a balanced person like Ishana's mom shouldn't have behaved like all the problem lies with Nikhil's family, when the problem is in her house (Ishana)!!!!😡.
I have a different take on her behavior :
Ishana's mom was against her relationship with Nikhil when he got married as she didn't want her daughter to get hurt and also because extramarital affair is immoral. She was trying her best to open Ishana's eyes to this reality. Ishana on the other hand went ahead and even lied to her mother a number of times to be with Nikhil. Being a single mom, She doesn't want to loose her daughter by doing things contrary to her daughter's wishes too. At the end of the day her daughter's happiness matters to her more than anything else. So when Laajo left, though she was not comfortable with Nikhil she let her daughter have her way , at the same time she took a commitment from Nikhil's family. Now after everything if Nikhil behaves like a flip-flop what can she do than blame his family!!! Yes her daughter is also to be blamed but she knows it already and she did all this for her daughter's happiness. Remember she said she has no one except Ishana to call her own in that scene when Ishana was trying out her red chunari. So her behavior to some extent makes sense.
Even I did not like when she told that Nikhil's family doesn't have control on him. Oh com'on , Nikhil is an adult and not a teenage boy that his family can control him!! I think now-a-days even teenagers don't like interference of parents!!!😆😆😆😆 So she is wrong in that and also to support her daughter's Love for a person who is confused !! LOL Yet she is sweet and caring.😊