Flu shots are grown through animal tissues like monkey kidneys, chicken embryo, and dissected organs of humen aborted fetus. So, yes she should be aware. It addition the flu shot contains mercury, aluminum, formaldehyde, other other toxins. If there is an allergy I would beware. Many people do not realize what the flu shot contains, but the information is out there if you research it. She can build her own natural immunity instead of getting a flu shot which would be healthier in general and because she has an egg allergy.
You can look up this information like I said, it is available and out there, but not really told to us unless we look for ourselves. I hope this helps!