Gender math

Drum roll...we had our ultra sound and in order to announce the gender of baby #3, I'm going to make you do a little math. :)

(Where D= Darrell and H=Heather)

Here are some hints if you don't know the years:
Sqrt[(Baby’s birth year - D & H wedding year) + (H’s birth year - D’s birth year)]

The answer will be the number of letters in the word "boy" or "girl" and then you'll know.