I think Shagun is dazzled and taken back by the rich life. I think it's just something she want's so much, and Ashok know's how to keep her under his control. He give's her everything she wants. I bet their will come a time way further into the serial where things will go bad with Ashok and she will try to get back with Raman, causing problems between him and Ishita but that won't be for awhile. I think like any mother, she does love her child but clearly she doesn't love her enough to go against Ashok. She fear's if she does, that she will lose all her riches. He has complete power over her now, because she knows if she goes against him that she will have absolutely nothing. No home, no family to go to, and she will be stuck all alone. That's what happens when you depend on a man, just as she is doing.