Dear Anne, Yes, babies fed EBM or who nurse have less chance of NEC.  Yes,
the milk becomes colostrum.  Some toddlers don't like the taste, while
others are thrilled with the rapidly abundant new supply (milk dwindles by
end of pg).  Pumping for new one and nursing toddler will probably help her
develop a very abundant supply. Will she have a c-sec?  If so, the few days
in hosp she can nurse newborn or pump exclusively for him/her so newborn
gets biggest share of colostrum.  Later pumping after toddler nurses may
help her pump higher fat milk for newborn.  I would assume that the other
bit about milk of premies being different would also apply for a while here
too.  I think I've read that the "premie" effect lasts for about 6 weeks.
Sincerely, Pat in SNJ