Find the Indicated Probability $\frac { 7 } { 8 }$

Find the indicated probability. Round your answer to 6 decimal places when necessary.
-What is the probability that a family with three children does not have three children of the same gender? Assume boys and girls are equally likely.

A) $\frac { 7 } { 8 }$
B) $\frac { 1 } { 4 }$
C) $\frac { 3 } { 4 }$
D) $\frac { 2 } { 3 }$