Step 1: On the day before her arrival make sure to do a reconnaissance of the kitchen to find the best position to place the chair so that she'll have a clear view of everything else apart from the oven you'll cook on
Step 2: Find a recipe book, a fine cuisine recipe book and leave the page of the hardest meal to cook open and placed in a position that when she walks thats the first thing she'll see.
Step 3: Stock up on spices and empty spice bottles (i doubt she'll check if there's any inside) and leave them in a very visible position to her.
Step 4: Once u start cooking make sure to use culinary terms like marinate or whisk the eggs to create the impression you know what you're doing.
Step 5: Make sure to talk a lot to divert attention from the fact that you're only making eggs.
Step 6: Make sure to move around the kitchen a lot and move the frying pan unnecessarily to seem busy.
Step 7: Place as many spices as possible next to the oven to make her think you'll be using them
Step 8: Once ur eggs are done pretend to have had the intention to use the spices and act like you forgot. Preferably promise to use them next time.
Step 9: Once done with the eggs remove the actual meal your mum had prepared from the fridge and warm saying that you had prepared that dish before and the eggs would just be a supplementary dish.