JOEL - A patriarchal Blessing is not a prediction nor an assurity of future events. As President Thomas S. Monson said: “A patriarchal blessing literally contains chapters from your book of eternal possibilities" (Ensign, November 1986, pages 66-67). He said possibilities; not probabilities.
And just as the Liahona in Lehi's time only worked when those using it were righteous and obedient; patriarchal blessings are similarly conditional on faith and righteousness. We can receive the promised blessings only when we follow the counsel and commandments. But assuming that your friend has done all this, and still finds herself without children, she may need to consider a more lenient interpretation on what it meant by "this generation". Things happen in the Lord's own time. Circumstances of life in "this generation" may cause a particular part of a blessing to go unfullfilled in this life time. I guess the most important thing to remember is that a patriarchal blessing contains things that could happen to us in this life or the next; not of things that absolutely will happen. It is healthier to look at it as a road map to follow, and of things to try and accomplish as we journey through life.