My mom has the flu, kids have been in close contact. they don't have their vaccine yet. should i get it now or is it too late ?

Influenza Vaccine: CDC and AAP recommends annual influenza vaccine for all kids 6 months of age and older. Children 6 months - 8yrs require 2 doses of vaccine during 1st season in which they are vaccinated to optimize response. Shot typically should be given by October, however, as long as flu viruses are circulating, vaccination should continue to be offered throughout the flu season, even in January or later.