My 4 year old daughter will only eat sausages, ham steaks and rissoles at dinner time and she has been this way since she was 18months. She will even try new food. Please help?

Hungry enough...they'll eat anything. Your enabling her control. No one ever died from getting to the point of being really hungry.

Children don't always like to try new thing all of the time. A lot of times they won't like something the first time that you offer it to them or they might not even want to try it at first. I reccomend that you continue to offer small portions maybe 3-5 bites of the new food and continue to offer it even if they tell you that they don't like it. I will even sometimes offer something good like a treat if they try it or eat the new food. After tasting the new food about 3-5 times you pretty much know if they like it or not.
Since you have been letting you daughter have her way at the table there might be a strong resistance of her trying the new food at first, but stay firm in your decision. My 2 year old would purposely vomit if I gave him food that he didn't want, now he eats anything I put in front of him and asks for more sometimes. While my 7 and 6 year old are a little bit more picky and my  two 1 year olds never gave me a problem at all.

You have to take charge here.You are the parent. Start offering her only one choice of a small portion of meat and more veggies. She WILL Eat them, but find out what veggies she likes. Her body loves meat because thats what her body remebers eating everyday but you have to change that. I have 4 children and they love veggies, but not at first they didnt. I had to change what I was offering.