Aaaanywaaay.... Back on topic:
I always thought that it was both.... Bess refused to live her husband, possibly also because she was terrified of descending in a small boat into the frigid black ocean. Meanwhile, little Lorraine would've been hysterical and quite terrified herself and would probably refuse to be parted from her mother. I bet by the time it took Bess Allison to find Hudson, realise that Trevor is safe and that there's no more time for stalling getting Lorraine on the lifeboat, it was too late.
In my theory, Bess and Lorraine probably WERE placed into collapsible A, but when the boat got swamped and washed most of the passengers overboard, the Allisons were probably sucked into the imploding windows, submerging vents or the open hole from the collapsed funnel... I shudder to think of it, such a horrific death!