Niece Alex is 5 months old and i have learned form her dad a week ago that she is still on a pure milk-formula-diet.
Weaning should be from 4-6 months, and remember that you start with blenderized food in thin consistency. Gerber is the most common that is used, if not natural food like boiled potato, carrots, banana, mango, apple, rice gruel and the likes. It is osterized and strained at first and slowly progresses to semi solid. Variation is necessary especially with the constipating items such as apple to ensure smooth flow of bowels. We may see weaning as letting the child adjust to more than just the taste of milk and the use of her tongue and mouth, it need not have to be filling right away and so start with just a teaspoon or two. Gradual introduction if I may say so. Ensure the cleanliness of the utensils to be used and practice proper sanitation like hand washing.