If she's worried about the feeding itself at night or waking LO up, could she try pumping once overnight? It sucks getting up or having sleep interrupted, especially when they don't nap well during the day, but if baby is pretty well guaranteed to sleep through, one pump session shouldn't be all that horrible, and it might REALLY help, at least in terms of overall supply.
It sucks not getting uninterrupted sleep (not gonna lie, I miss it), but for me it came down to deciding that nursing was more important and making that commitment to it. When LO slept through for a while at 2 months, I got up and pumped instead. Then he went back to waking up, which I honestly find much easier/nicer than pumping, even if it means interrupted sleep.