We went to the park about a week ago with DD1&DD2. DD1 got in a mood and walked and sat on a bench near a pond. (Still in sight) but I couldn't leave DD2 so I stayed with her. When DD2 got tired I brought her over to DD1 a frog was jumping around the edge of the pond. DD1 threw a stick at it, however it didn't go so she threw a rock. it hit it on the head and died. (DD2 didn't see luckily) so I got DD1&DD2 away quickly. DD1 tried to shrug it off but the last few nights she has woke up screaming and got into my bed. When I ask her what it's about she just shakes her head and mutters about the frog. IDK what to do? help?