Since your daughter is 2 years, her expected weight should be around 12 kg. However as you mentioned, she weighs only 9 kg. This is 75 % of the expected weight for age. So your concern for the child is genuine.
Children of this age usually have nutritional problems as they do not eat well and forced feeding is not recommended. The most common being iron deficiency anemia
At the same time, children go through a period of rapid growth and if they do not eat well, they look tall and thin.
If your child has a good appetite, you must ensure she gets a balanced diet. Iron rich foods must be introduced in her diet like red meat and liver
along with green leafy vegetables and fruits like apple and watermelon.
Avoid all forms of junk foods and carbonated drinks.
Apart from what you are already giving, you can also add an egg and 2 slices of bread with butter at breakfast.
Also during evening, add some snacks like biscuits which can give her requisite calories for the day.
Just as a stand by, you can ask for a simple blood test
to make sure she does not have any iron deficiency anemia.
I hope I have answered your query.