In a mixing bowl, place lemon juice and sweetened condensed milk. Beat well until thick. Pour mixture in the pie crust. Cover top with whipped cream and sprinkle graham cracker crumbs over the top. Place in the refrigerator until time to serve.
Note: my mom's recipe says place in icebox to chill. It also says to pour mixture into a pie pan lined with graham crackers :-) Thank goodness for the invention of the already made pie crusts!!