My son was born at exactly 32 weeks after 2 rounds in the hospital for me so I know exactly how she is feeling.
Depending on when the baby is born he/she may need to stay in the NICU until they can maintain their body temp, breathe/suck& swallow while keeping their heartrate up while feeding, obviously breathe on their own, keep their heartrate consistent. Having the steroids on board will make a huge difference. My son was on the vent for less than 24 hours and on the CPAP for less than 24 hours because I had been given steroids.
I would not have wanted a baby shower while my little one was in the hospital. It would have upset me even more. I cried and cried the day I had to come home without him. To have a shower while he was in the hospital would have made me a wreck. And no, baby should not have tons of people around he/she for quite some time depending on what week they make their arrival.
Offer to drive her to the hospital, make food for them so they can spend as much time with the baby at the hospital as possible.
I was die-hard dedicated to the idea of breastfeeding. Be her advocate or make sure her partner knows to. Have them bring a pump in as soon as possible after delivery! And she needs to pump every 3 hours just as if baby was nursing. If she really wants to breastfed you can't skimp on this. That is what gets the production going! I highly recommend using the medela steam bags to make cleaning all the pump parts quick and simple. Those would have been a dream for me to have with my son!
For the actual nursing part-have her try to nurse baby as soon as it's physically possible for baby to try. We never got to much while my son was there for the 6 weeks but I kept pumping away and building my supply. Once we got home I worked to get him to the breast. It took about 6 weeks and then he got it. I went from the hospital bottles to the Playtex nurser with the brown/latex nipple. It is very soft like the breast and with the drop ins it allows mom to squirt just a tiny, tiny amount of milk in baby's mouth so they know they the different nipple is there. I also fed my son with my top and bra off and when I burped him I switched sides just as if I were nursing him. The we started trying the breast at feedings and he eventually got it! He nursed till he was 16 months old.
These are the things that I did and that worked for me. It was a tremendous amount of work in the beginning but then things slowed down and became more normal. My son had some other things going on not really related to the prematurity that added to me feeling like I was running a race every day but my hubby and I managed and so will your sil.
Best to them!