My DS#1 refused to feed himself til he was about 18 months old, and then he refused to "bite" things like sandwitches - we had to break off bite-sized pieces and put them in his mounth. I have since just realised that this is a funny facet of his personality - he doesn't like to try new things until they have been proven to be fun, necessary or non-scary.

I wouldn't be too worried about her - all kids do things at different times and most kids do funny little things