In vitro?
Nah, in Los Angeles.
I'm not sure it's in vitro. Women at 40 can be fertile with multiple births. Ovulation is hit or miss at that age. Some months there's no ovulation, some months multiple eggs.
More than likely she was taking clomid or one of those drugs.
Of course, she could have been eating a lot of sweet potatoes. They are filled with follicle stimulating hormones.