A good tip Steve gave to me...The more food you put into a dog, the more poo you will have to pick up.

If you stick to a good quality dog food that agrees with your dog, weight gain is always gradual, it never happens overnight.
I use Burgess sensitive and you can buy that at Pets at home, it is great for bunging up a runny bottom. I also add lots of different foods when I feed up (not all together). I only give a little pasta as this can make them more loose. They only get 1 sardine each in their main meal a couple of times a week. Corned beef is a favourite and also mince stew, Yorkshires with veg (1 spoon with meal). I have even added tinned dog food in to their meal just to give it taste.

Daisy Mae will be having a moult at the moment (most dogs are) and this is where the dandruff is coming from. A good comb to buy is a stripping comb (pets at home £5-£6). This comb is fab and I do all my dogs at least once a week with it. and then give them a buff with a towel, they love it.
Don't worry about the stiffness in her legs, it is just because she is not used to exercise. The trainer who had her, did not walk her a lot. Tinned tomatoes or a little cod liver oil is good for stiffness and cramps.