Jason, I think some of her plants will re-leaf, and/or have stem die-back. I still think more, though, could have come through the cold spell, unscathed, if things were done differently.

Just like others in the country (myself, included), who have gone through several mild winters, and thus, spoiled, believing that climate change means that EVERY WINTER will be mild, going forward, are shocked when ONE regular winter pops up.
The irony to me, though, is how she believes that there "was nothing she could have done differently", to have prevented what happened, from happening.
Firstly, she should have realized that her zone is STILL z9b, which means she should still expect winter minimums that will dip to at least 25 degrees. Knowing this, should have made her realize that anything in her garden that has already been tested by others (many plant species hardiness minimums, at which damage shows, are already documented) to receive damage, at or below 25, will need to be protected, if at, or near such lows are expected. While it can be true that a species may behave differently, at different minimum temps, than others, she could have been better prepared should a "danger zone" temp occur, unexpectedly, rather than just "wait and see".
Secondly, I guess, because she has quite abit of land, on which to plant, allowed way too much space between tree plantings, which would make protecting a number of trees, at once, way more difficult (for instance, using a "baseball park style" tarp, to cover the "overall less land, but high-density fruit tree" area, taking up less land, than she currently has planted, but heated, as she did for a relative few number of individual plants). Even though she kept most of her tree heights, relatively low, through pruning. Her yard , even with her "160 fruit trees", could have doubled or even tripled the number of trees, in the same amount of space used, if she planted them closer, in a high-density form. She would get less yield per tree, but higher yield, overall. Depending on what she was doing with her crops, (unless she was selling or giving them away), was probably too much for just her self, or family, anyway.
Thirdly, she discussed "saturating the ground" around her trees, before the freeze, with water, because the tap water temp was much warmer than the air temp was, I guess in an attempt to keep the soil temp above freezing. HOWEVER, some fruit trees (for instance, mangos) require LESS SOIL WATER, in cold weather, than during warmer weather. In years past, Florida citrus farmers, would use ABOVE GROUND sprinklers to wet the above ground parts of the trees, when frosty, freezing temps were forecasted. A water coating, in the form of ice, on leaves, etc., actually insulates the plant, kinda like snow does, against below freezing temps, in more temperate areas.