I agree with the others that this result may not be accurate. Dartmouth will likely want the financial info (income/assets) for all 4 adults (including the step-parents), even though their NPC didn’t specifically ask for that. Did you include that info? Are the owned properties farmland or vacant land? Or business investment, like apartment buildings?
I agree you should ask Dartmouth and any other schools on your list if they will do a financial pre-read because of the complexity of the situation. I don’t think Dartmouth routinely does financial pre-reads though, nor do most schools. But, still ask…call the FA office and say your family financials are complicated by divorce, remarriage, and multiple investment properties, and you want to have an accurate COA estimate before applying ED, so can you please do a financial aid pre-read (or help with the inputs on the NPC).