Personally, if both you and her Dad are below average height, then I wouldn't worry. These figures are always based on averages which don't work at either end of the scale. If you are feeding her a well balanced diet you can't really do anything more than that!
I think this is another example of scaremongering. For these figures to work correctly they would have to do a scale for every combination of heights from about four foot eight upwards - how else can they be accurate?
If you don't like what you see - don't look!