My sister in law gave birth to twins 2 weeks 3 days ago at 26.5 weeks
gestation. They were born via c-section because of an incompetent
cervix. The babies are holding their own and are now above birthweight
(which was 1 lb 12oz for one and 1 lb 14oz for the other).

just wanted to say here that it's not normal to give a c-section for an
incompentant cervix, more the babies are going to be born because the cervix
is incompetant and the position or health of the babies means delivery needs
to be by c-section, you could try posting on misc.kids.pregnancy, there is a
lady known as Paula J who had 26 week twins and pumped for them.

She is pumping every three hours and is getting about 12oz in a 24 hour
period. The babies are now taking 12 oz in a 24 hour period. So she
needs to increase her output.

the first thing that strikes me is that I've always heard you should pump
every 2hrs with a newborn, they would usually feed that frequently, so you
have to mimic that. Is 12oz the most she has produced? it surprises me, as
when I was pumping (but also fully breastfeeding), in the mornings, even
after feeding Ada, if I didn't check on the pump and stop I would get that
much in about 10 minutes, admittedly it's my 2nd baby, but when your milk
comes in you usually have gallons of the stuff, so it makes me wonder if
either her milk hasn't come in properly, or if she is not responding to the
pump. Do they do Kangeroo care, where they put the babies on the mum or dads
bare chest, it is good for the babies and for the mum's milk supply. Where
does she pump? often a photo of the babies can help, if she is away from the
babies.

I'd need more details, such as what type of pump she was using, how long
each session is etc. but like everyone else, I'd recommend trying to work
with and LC on the spot.

Anne