I agree with the others that you probably have nothing to worry about as HCV is transmitted by blood to blood contact. However, it does not take "a large amount of infected person's blood", in fact it can be transmitted by a minuscule amount of blood (i.e., accidental needle sticks in a health care worker). If you are very worried (and as a mother I can relate), discuss it with your pediatrician for professional advice.
Sounds like a pretty nasty restaurant though... I would avoid dining there in the future...
Polina, it is impossible for your girl to get hepatitis C this way. Hepatitis C is transmitted through blood to blood contact. This means that pretty large amount of infected person's blood has to enter another person's bloodstream. That is why the common source of infection are blood transfusions and different injections.
Even if you didn't wash your daughter's hands, she would not be infected.
I have my own little girl, so I understand how concerned you are. My husband has this disease, and our daughter, of course, is in every day contact with him, as well as me. We don't have hepatitis C. This disease is not as easy to get as you seem to think.
Your daughter is OK, and you don't need to worry or to test her.
Here is the information that has been put together by MedHelp on the causes and risk factors for hep C:
http://www.medhelp.org/medical-information/show/69?section_id=25676#sec_25676