How much exercise per day a appropriate for a 4.5 yt old girl? i don't want her to exert herself too much

Don't worry........!: Unless your child has some type of cardiac problem, there really is no such thing as exerting herself "too" much. The great thing about kids is they will settle down if they are fatigued - they can drop right down in the middle of the park and take a nap to recharge! Let her run, climb, jump - encourage this type of healthy lifestyle. If you start to try and restrict her , she'll get wrong message