How demanding is a job is emergency-care nursing?

The best answer to this is what are your most passionate about and what pace do you like to work at. Emergency nursing is fast paced and requires quick thinking and actions of the nurses for both kids and adults. Pediatric nursing (assuming you mean non critical care) can be slower pace and often focused on observation (again assuming the child is not acutely or critically ill) and family education. If you like fast paced but really like kids, consider a pediatric emergency department. Many hospitals are opening kids only ERs where your oldest client would be 17-19 depending on the hospital. I actually worked in the Adult ER because I really liked working with adults more than children but loved the fast paced nature of ER. It really is up to you. Good luck in making your decision...and always remember your first job will not be your last. You will have a career span to find your niche and place that you really love.