Yep it is in mother DNA, part of their job description, what they do; worry. People most often display unconditional love towards their children. The loss of any child is one of the most awful things a parent will ever have to face. So their worry for the safety of their children is absolutely understandable. However for life to evolve children have to colour outside the lines, bend the rules, do outrageous things because they do not know any better or for want of a better description, live life. So it is absolutely understandable that children do lots of things that cause worry to parents, especially mothers.
As for the fear factor generated by terrorists I think the media have an element of responsibility. If the media focused on the hundreds or thousands of people killed weekly on the roads of the world in the same way as they do with terrorists, then we would all be afraid to get into our cars. Ditto for holiday deaths world wide, ditto for drug and alcohol deaths. I suggest that we say no to fear and live our lives the way we wish to live them. Of course take sensible precautions and pay attention to your environment but say yes to life.
We all have to die some day, in the mean time live this wonderful life as best we can.
Buen Camino.