DJT this topic is an excellent example of how the question should always be " what are the owner's goals" . I would not start over because of the situation. I note that there was no mention of fishing in the post so that must take a back seat to "Mom" as it should. Like Bill says this is about her not the pond's fish. A seine survey would help gather info and be a way to remove some of the offending Fx HBG. I would add some 8in LMB (20). If you have that many Fx HBG then my guess is you have HBG that are a high % of either GSF or BG or some GSF/BG are in the mix. Studies on the subject wrt HBG in ponds where there are even a few LMB present show almost no Fx survive to a year.