Hi Im a BusyBee, The earlier you make your christmas cake the better! Your mum was right. You use a fine skewer to poke a few holes in the top of the cake and then using a teaspoon, carefully pour a bit of brandy in each hole. Put the cake back into its airtight tin and leave it for a week, then add another teaspoon or two of brandy,
You can marzipan it one day, then ice it another day, say the week before christmas and restore in the tin until needed. When the cake has been cut, again, you store in the airtight tin to keep it fresh. Hope this helps, good luck and happy cooking.