I don't think Radhika has forgotten the ema...but what she probably meant was after Nandini succumbed to cancer, he singlehandedly raised Pari, which I'm sure wasn't easy...Mauli had dida and Mumma, but Kunal was all alone...coupled with the responsibility of pari, he probably was also guilty of betraying Mauli and this does take a toll.. .So indeed Kunal has suffered, though it was of his own making.
As a mother I don't fault Radhika... It wouldn't have been easy for her to let go of her son but she did that as that was morally correct...it takes immense strength to do what she did...and now since he's here, she is not able to control herself...
I think writer should give a brief update regarding what happened after Kunan marriage and their life in london...