Dd who Is 6 had flu a few weeks ago that had left her quite washed out. Over the last week or so she has occasionally mentioned that her heart is beating fast. It doesn't coincide with exercise. When I reach over and take her pulse it seems within the normal range of around 90 beats per minute. I am not that confident but I have tried a few times and think I am counting correctly. Wwyd? Is it worthy of a Drs appointment?