But you might want to check with your dotors on that swim ring around her neck that she was wearing in the pics.. I am afraid it could press on her carotid baroreceptor which is located around one's neck, and that could cause a sudden drop of heart beat.
Here is a picture of where carotid baroreceptor is located:
http://www.google.com/imgres?imgurl=http://www.pharmacology2000.com/Autonomics/Adrenergics1/baroreceptor-carotid1.jpg&imgrefurl=http://www.pharmacology2000.com/Autonomics/Adrenergics1/Adrenergic-1.htm&h=720&w=960&sz=64&tbnid=8AL-BGPkc4EfYM:&tbnh=90&tbnw=120&zoom=1&usg=__2YBrmn8rtpPUmHdM3LU2hbqLoOk=&docid=4uvspZrxkCcFmM&sa=X&ei=vE0mUrfwFO3UsATHxYD4Cg&ved=0CFgQ9QEwBw&dur=10
Just because it's a commercial product doesn't mean it's safe.