Yeah, she should have thought about this. But she too, like Abir, thought that Meenu did something to cause him to run away. That's why both had been behind Meenu and gave her ultimatums to get Kunal back. What they are failing to understand is that Kunal is not a child; and they shouldn't put the blame on Meenu for everything.
Parul wasn't trying to be selfish or manipulative. I don't think she wanted to hurt Kuhu. But she is blinded in her love for her son and is not thinking that her son could be in the wrong; that he isn't in love with Kuhu like he claimed.
For me it is Meenu and Kunal who are manipulative. Parul was genuinely happy to get Kuhu as a dil as she thought she was perfect for Kunal. She was always worried that Meenu shouldn't do anything to break up the marriage. I don't think she is malicious but just thought that Kunal was nervous on his wedding day and was unhappy about Mishti's presence. I am pretty sure she will be disappointed to see Kunal misbehaving with Kuhu. Kunal and Meenu at times have treated Parul like dirt.