mine were 29+ weekers, but stayed together throughout - I was 20 mins away, so visited everyday. What she needs to remember is they will not remember this part of their lives, so she should just make the most of the time she does get with them - skin to skin, feeding, changing, cuddling, and then focus on herself when she is not with them.
Keep lots of photos nearby for expressing (it helps with the let down reflex), and for general cooing over. My boys were home after 8 weeks in scbu, and are now 3 and you would not know any different, they are just a little bit smaller than your average 3 year old.
Although i was with them everyday, I still made time for myself and feel I had a bit of a jump start when they came home, in that I was fully healed, I had been eating properly for 8 weeks and the house was ready, so when they came home all I had to do was focus on them.
She got a roller coaster ride ahead of her, point her towards this board if she has internet access, as we will help her get through the times when she can't be with the twins.
Good luck to her and love to you for being such a caring friend.