The proper pruning of wisteria is once in July to remove the summer's rampant growth and again in March to prune it back to flower spurs and to keep its structure....
It is unnecessary to prune it continuously.....
My wisteria will bloom more than once per season sticking to pruning it twice......

I disagree with the advice above :-) While that is the 'classic' advice, in my experience with Chinese and Japanese wisteria (I have not grown either of the American types....) more frequent (weekly - even daily - at times of rapid growth!) pruning does not harm them and does promote the development of the spur growths associated with flowering. Both my wisteria 'trees' did their first big flush of spring flowers at 5 years of age and the show just keeps getting better. The Chinese one will repeat flower in the summer and it is very noticeable that, when you cut back one of the new whippy stems, usually a flower appears 7-10 days later near the end of the stem that was cut.... The only time I've found that it is not good to prune a wisteria is in the spring before the Chinese one flowers - that triggers a flush of new foliage that hides the flowers. A couple of years ago I wanted to shorten the 'tree' so pruned it early in the spring when the branches were bare so it was easier to see the structure and decide where to cut it back to reshape it. It bloomed that year but the huge flush of foliage happened at the same time as the flowers so many of the flowers were hidden. The Japanese 'tree' needs foliage pruned off when the flowers bloom as the foliage naturally emerges early and can hide the flowers. IMO it sounds like your friend is doing the right thing and she shouldn't worry about pruning hard. If she has an American type, they are supposed to bloom on new wood, so pruning would help with the development of lots of new wood, I'd think.