To be fair to this story, I only read the opening chapter so my comments should be seen in this light. The story might pick up but, I'm afraid I worry when a thriller opens with the weather., especially when the chapter ends with a good cliffhanger. To make it work there needs to be more edge and drama. The mother and daughter seem a little forced, although you can sense that something dark has happened in the past.
I was surprised that the mother didn't know which college her daughter was going to but maybe she hadn't seen much of her. You would have thought they would have talked about it during her visit.
The cliffhanger 'Do I have a brother?' works but for me to stifle a gasp and want to read on the characters would need to be stronger, better drawn and the tension electric.
There were one or two typos and other errors; 'naval' instead of 'navel', for instance.