The discount per one ticket is 10 * 30/100 = $<<10*30/100=3>>3.
So Dorothy's and her brother's tickets are cheaper by 2 * 3 = $<<2*3=6>>6.
Her family consists of 5 people, so the ticket cost stands at 5 * 10 = $<<5*10=50>>50.
Including the discount will lower the price to 50 - 6 = $<<50-6=44>>44 in total.
Dorothy will be left with 70 - 44 = $<<70-44=26>>26.
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