Androbob - The lowest PPs starters at Frankie and Benny's are a prawn cocktail for 7, a tiger prawn skewer for 5 or Bruschetta or a crab cake which are both 8PPs. Avoid the skins! Goat's cheese one is 15, BBQ chicken, sweetcorn and cheddar is 16 and the bacon, tomato, onion and cheddar one is 18.
The house pizza Margherita is the lowest PPs pizza at 18. Hawaiian, BBQ chicken and BBQ meatball are all 21 and American hot is 22. All the rest are higher. Speciality pizza start at 29PPs for the Californian club. Lowest PPs Calzone are the New Yorker and Siciliana at 24PPs each.
I went to Frankie and Benny's a few weeks ago and had the omelette and asked them to leave out the cheese. It comes with a small side salad and fries but just a handful. It's not listed in the Eat Out guide though so can't tell you the PPs I'm afraid.
Lowest point main meals are the Penne Arrabbiata for 11PPs, Spaghetti Bolognese for 16 or House Speciality Sausage and Mash for 15PPs.
Sorbet is just 5PPs and the next lowest PPs pudding is either Eli's Caramel pecan cheesecake or vanilla cheesecake both at 12PPs.
Hope that helps. 
Norma - 6lbs! Amazing. You must be over the moon. Well done you! 
The potato thing.... A raw 225g potato is 4PPs. Some of that weight is water. A baked potato at 225g (6PPs) will not have as much water in so there's more potato making up the weight. Your raw 225g potato would weigh less than 225g when it's cooked as it would have lost water during cooking.