See my signature. I have donated to an adopted baby after the birth of my son and then I tandem nursed my son and adopted daughter. I started pumping when my son was 20 months old. She was born almost a year later. I had a freezer full of milk I stored. Sadly I lost 75% to a freezer accident so needed to receive donor milk.
Can she induce lactation and you supplement what she makes? That would be best. She would be making milk fresh and as the baby nursed from her, her body would make antibodies to whatever germs the baby had been exposed to. See http://asklenore.info/breastfeeding/induced_lactation/adoptive_breastfeeding.shtml for more info on the Newman protocol for inducing lactation.
Your milk will be fine for the baby. Remember, I was almost 32 months post-partum and I made just fine milk.
You should start pumping now. It sounds like you haven't pumped before. You don't know how your body will respond to a pump. I could rarely pump more than 2 ounces even when my son was very little. Other women can pump 12 ounces without blinking an eye. You may be able to hand express just fine, I certainly could NOT, but have known women who could. A hospital grade pump is lovely, but they're expensive. Maybe rent one for a couple months (our local hospital charges $35 a month) to see how this all goes before investing in a pump. Last I heard, many women do fine on the Medela brand for consumers.
Freeze the milk you start pumping TODAY in lansinoh milk bags. Target sells them. When I was buying them, I found them cheapest at amazon.com. You lay the bags flat in the freezer for easier storing. Donating etiquette is she should pay for the bags. Maybe even a pump if you're going to do this long-term for her. I HIGHLY recommend you get tested for all the milk bank diseases. Even tho my recipient mom said I didn't need to, I got tested before donating. I am a nurse and know people can have germs they don't know they have and I would have felt awful if I gave her baby something. Here's info on blood tests: http://milkshare.birthingforlife.com/donorscreening
She can arrange to receive donor milk from others besides you since chances are small you'll make all the milk she needs (though you certainly might.) She can get donor milk at:http://milkshare.birthingforlife.com/ and http://www.eatsonfeets.org/
She'll want a lactaid http://www.lact-aid.com/ so she can nurse the baby while using donor milk. My milkbaby's mom wasn't able to make any milk for her adopted babies, but both babies nursed at her breast using a lactaid.
I took domperidone to increase my milk supply. Also Motherlove's more milk special blend. Get the liquid ALCOHOL FREE. Liquid is cheapest and alcohol free doesn't taste as bad as the one with alcohol. http://www.luckyvitamin.com/p-3059-motherlove-more-milk-special-blend-alcohol-free-8-oz?utm_source=googlebase&utm_medium=fpl&utm_term=MotherloveMoreMilkSpecialBlendAlcoholFree8oz&utm_content=51932&utm_campaign=googlebase&site=google_base&
I found the best way to take it was to measure it in a syringe, put it under my tongue, and drink a bit of water with it. It tastes like burnt maple syrup. You can get capsules, they just cost more.
Like I said, she should induce lactating and use your donated milk, and possibly that from others, to supplement what she makes. If her baby is due in December, now is the perfect time for her to start. If this baby is via a surrogate, see if the surrogate will pump as well. If this baby is a straight adoption and it falls through, all the milk she and you make can be kept frozen until another baby comes along. I have a stand alone freezer and used milk up to 18 months old. (Make sure you date all the milk you make so she can use oldest first.)
Let me know if either of you have more questions.
My daughter turned 3 in August. She is still nursing. I stopped making milk after I stopped taking the domperidone. She gets watered down light coconut milk through a supplementer whenever she wants to go to sleep and first thing in the morning. (She can't do dairy milk.) I hope she nurses long enough that she has memories of how wonderful nursing is. She had less than 2 ounces of formula in her life. I got to the hospital and started nursing her at 6 hours of age. It has been a totally wonderful experience.