Answer: 49 cookies
Step-by-step explanation: 7 dozen= 84 , so subtract 84 by the 2 cookies she ate and you'll get 82, now 2 dozen= 24, so now subtract the 24 cookies that she gave to her brother by 82 and you'll get 58, then subtract the nine cookies she gave to her mom by 58 and you'll get 49 cookies.
so basically,, 84-2= 82 -2 = 58 -9= 49
I hope this helped :)