What it means is, when she sat in a restaurant in years to come, 10 years to come, 15 years to come, or she's on the beach, every so often she's going to start rubbing her skin, and out of there will come a piece of that shrapnel.
Significa que durante los próximos 10-15 años, cuando esté en un restaurante, o en la playa, y se rasque la piel, se arrancará otra pieza de metralla.