I also vote for the BM-specific freezer bags! The purple box (Lanosinoh brand) seemed to be the best. date and measure before freezing. Lay flat to freeze, then stack (in containers by month) and use the oldest ones first. In a regular freezer, they say 5-6 months and up to 1 year in a deep freezer. I had some that were just over a year old and the place I donated (I had over 1,000 oz) still took them.
If she wants some details... my schedule was something like this (I went back to work when dd was 9 weeks old):
~6am early nurse, followed by a pump (a few oz)
8am at work
10am pump (several oz)
1pm pump (several oz)
5pm home nurse, followed by a pump (few oz)
then, nurse on demand at night (~every 3-4hrs).
Of course, there were times we'd be nursing every hour, and some times she'd go 5 or 6 hours without... just depends on the baby.
I would usually pump after each nursing session (squeeze out a few oz). I was also a pretty heavy producer. After pumping (I'd pump into a hard bottle), mark the bag and put in fridge (if to be used soon) or freezer (if I already had some in the fridge). I'd take fresh (day before) milk each day and also kept some in the freezer at daycare. They used everything. By the time we stopped BF, right at 1 year, I had over 1,000 oz in the deep freezer, so I donated it to a place in TX for preemie babies.
Tell your friend that she just needs to find her rhythm and do what works for her and her baby! Everybody is different (mama and baby)!