So sorry to hear of your friends loss.
My daughter lost her twin boys at 21 weeks (can I ask, were your friends twins monoamniotic twins by any chance?)
Like ethanryan has already said- you can either hold your own funeral, or let the hospital deal with it, which usually involves cremation and something put into the book of rememberence.
If your friend does want a funeral (my daughter did) I think all funeral directors will do this free of charge for you (I know it was in our case) and you only need to cover the cost of the actual cremation which is minimal. I know it's horrible thing to think about, but if it is a funeral your friend wants, she can be assured that costs wont need to be a factor.
I'd also recomend gently to her if you can, that it might be a good idea for a post mortom on the babies.
My heart really goes out to your friend as it brings so many painful memories of what happened to us just before Christmas.