Melissa,
Does your friend realise that she will be carrying those germs back and
forth as well?  She can protect her larger twin by frequent handwashing
(and requiring anyone who touches her baby to wash their hands first),
and keeping her baby in a sling so no one can breathe/cough on him/her.
This takes care of the two largest sources of germs.   Does she
understand that she will make antibodies in her milk to any germs she or
the baby comes into contact with?
        Another issue is the development of attachment to twins.  Research has
indicated that mothers attach first to one twin, then the other,
particularly when the twins were unanticipated.  Perhaps your friend is
bonding more to the smaller, more vulnerable baby first, and is
therefore more willing to leave the other baby behind for now.  This
might seem callous, but is actually normal. Perhaps talking with her
about these issues in a non-judgemental way can help her recognize the
psychological forces at work so she will have more free choice in the
matter.
--
Catherine Watson Genna, IBCLC  NYC  mailto:[log in to unmask]