There are no tricks, no tips, no handy hints, sorry. Just plain ol' physiology.
If someone wants to increase their milk the only thing that will do it with any degree of certainty or effectiveness is to increase the frequency with which the baby removes the milk - that is what drives supply. The baby has to be on in a way that allows him to do this properly, too.
All the other stuff - herbs, teas, beers - is piddling in its effect if the physiological basis is not understood or acted upon!
In desperate cases, there is medication which can boost prolactin but this has to be used in conjunction with frequent, effective feeding.
Some mothers are told/feel they don't have enough milk. This can be the case, it's true, but often, they are doing just fine.
There is no truth that cutting down dairy (or increaseing it) will have any effect on supply, either. Plenty of people will have individual foods or drinks they feel made a difference, but I feel in most cases it is co-incidence.
Eating, drinking and resting will not have any effect in most people.
Perhaps your neighbour can call one of the bf helplines?