Without even knowing about Ishwari's reaction to DevAkshi relationship, Neha already know her mother will not be happy with it.
She is the one who's actually aware of her mother's possesiveness for Dev. She's aware of her insecurities. We have seen at many instances she has mentioned that Ishwari doesn't like when anybody comes between her and Dev. She knew her mom wanted to spend some alone time with Dev and the gift didn't matter to her.
And even today when Dev said maa is happy. Neha knew that's not the case. And at the end when Riya asked Neha whether everything is fine she was thinking of Sona and said as of now all is fine but don't know how'll it be after sometime.
She knew her mother will not like to have Sona in the family photograph.
I want Neha to be the one to make Ishwari understand she's been unfair to both Dev and Sona. Neha can do it very well. As she doesn't fear of saying what she feels..!!