Recipe(tried): fruit cake - question

But it has been years. This was my deceased mothers recipe. no one seems to be able to make it as good as her. Please tell me what we are doing wrong. 1 LB. Butter 1 LB.Pecan meats 1 LB.Brown Sugar 1/2 LB Candied Cherries 1/2 LB Candies Pineapple 1 tea. Baking Power 6 eggs (separated) 4 cups flour.1&1/2 oz. Pure lemon or Vanilla Extract.
Cream butter, add sugar & cream well.Add egg yolks one at a time, beating after each. Sift 2 cups flour with baking power, add alternately with extract to creamed mixture. Use remaining 2 cups flour to dredge the fruit and nuts. Beat eggs whites stiff and fold in. Let batter stand over night at room temperature. The next day pour into greased tube pan. Bake 3 to 3 1/2 hours at 225* Cool in pan about 15 minutes to allow butter to be absorbed into cake. Invert and allow to finish cooling in pan, so the butter can drain back through the cake. My sister says my mom would cook this on Thanksgiving and leave in refrigerator untill Christmas. Would that make a difference?