My Big Sister

I do not get along with my husband's family very well, but in the beginning it was different.
His mother talked to me once in a while. Anyway, my husband has a twin sister named Barbara and they aren't especially close and their mother never talks about their father or the rest of their family they don't really know. You see, their father died when they were only 11 and they are the youngest of 8 kids (or so they always thought).

We were sitting in the living room of his mother's apartment talking about his sisters recovery. She had a routine surgery that went very badly and it was a long recovery for her. During the course of the conversation we starting discussing out of body experiences, because her brother said during a surgery he had a year earlier, he had an experience where he saw himself on the table being worked on during the surgery. A few minutes later, their mother came back in from the kitchen and asked what we were talking about and we told her. She made it very clear she does not believe in things like that and got really obnoxious sharing her opinion with us. Barbara looked at her and asked her who Bethany was out of nowhere. She looked at Barbara and said, what did you say? Bethany mom, you know who I mean, don't you? Barbara went on to explain that during her surgery, she saw her father and he had Bethany with him. See, Barbara died on the table for about a minute and a half during the surgery, but was revived. Her mother (who was still standing beside a chair) fell back into the chair and just sat there for a minute unresponsive to the rest of us. After she snapped out of her daze, she asked Barbara how she knew about Bethany, and Barbara said when she saw her dad, when she was being revived, he had Bethany with him and they were both fine. Their mother told us for the first time Bethany was their oldest sister. The firstborn. She was stillborn. Their parents never thought any of the other kids needed to know. I asked my husband about her and he never heard of her either.
To this day their mother won't talk about her.