How did your dinner go with your friend?
I know for me, much had to do with lack of support from professionals and other mothers that knew how to breastfeed. Combine that with some stubborness on my part to not demand help right away and to be scared into supplementing and I was in a situation that could have easily ended with 100% formula. There are so many little things that can go wrong with newborn nursing and when the mother is also unsure and easily influenced by medical professionals that quickly leads to supplementation and eventually formula feeding when the supply is not properly established. Did she have flat or inverted nipples?
I would say that in the hospital, it is SO important to have a plan that includes breastfeeding and advocates to support that plan. A doula is a good idea and educating dad is also a good idea. Having canned responses practiced is essential: "we are delaying the newborn exam for now." and "the baby is rooming in with me, no need for the nursery, thanks." Don't let that baby out of sight or it may receive sugar water and/or formula despite best efforts. I do think that skin to skin contact and latching within the first hour is key. With my first, there was no latching in that first hour and she fell asleep and after that had zero interest in trying to latch on. With my subsequent babies, I got them latched on within minutes of birth and that was MUCH better.
Once home, I agree with the tactic to not have formula in the house. This makes it not an option and forces mom and dad to be in it 100%. Dad is so important... he needs to be totally supportive, encouraging, helpful, knowledgeable, and steady. No "it's okay if you can't do it hon, I'll just get the formula." He needs to know the phone numbers of the LC's, LLL leaders, and mom friends to call when things get tough.
Another thing is to prioritize. There are always many things for a mom to do all at the same time... cooking, cleaning, diaper changes, tending to older children, laundry, etc. I would recommend prioritizing tasks so that she can focus on establishing breastfeeding. Maybe that means no cloth diapering for the first month or so. Maybe that means getting meals frozen and a meal train/food tree set up. Maybe that means organizing play dates in advance or getting her older child into preschool (how old will s/he be?). Maybe that means hiring a postpartum doula for a few weeks. She needs to be able to put her energy into being skin to skin with baby as much as possible, wearing baby as much as possible, being free to nurse on demand, and being relaxed enough to let her body heal and produce milk, etc.
Lastly, she needs to know where to get support when her husband isn't around. A friend like you will be invaluable. Just being around other nursing women is so powerful. I would also encourage her to attend LLL meetings (before and after baby is born) and join online forums like this one (before baby comes) so that she can ask questions as soon as they arise and hear from more than just you that she can do it. Keeping in mind that only about 3% of women truly cannot breastfeed is an inspiring reminder that the vast majority of breastfeeding problems stem from lack of support and knowledge in today's modern society.