Hello, I Am A Woman 73 Years Old And I

Hello, I am a woman 73 years old and I did get a flu shot in the fall. I picked my grandson up from school yesterday and just learned he was diagnosed with Influenza A this afternoon. Several questions: With a flu shot should I be concerned that I will get it? On Easter, I am suppose to be with one person who is 90 years old and two individuals in their 80's and a 2 year old. Is it safe for me to be around them?
What is the incubation time frame to catch it?