Great Dane height

Question
I have a black dane puppy who is 3.5 months old.  I am worried that she is short for her age.  She is 17.5 inches tall and should be 23.5 inches at 4 months (at least by what I have read).  She's not going to grow 5 inches in 2 weeks.  Is there anything we can do or any supplement we can give her to increase her height??  

Answer
Do NOT supplement her diet.  A slower growth is actually better as it is less likely she will have joint problems.  Not all dogs fit the standard and females are always smaller than males.  I would let nature take its course-- Danes grow VERY fast as it is.  She will continue to grow up until 2 years of age.