Charla completes \( \frac{2}{3} \) of the area in \( \frac{1}{2} \) hour.
To find out how long it takes her to complete the entire area, we can set up a proportion based on the work done. If \( \frac{2}{3} \) of the area takes \( \frac{1}{2} \) hour, then we can find time \( T \) to complete the entire area using the formula:
\[ \frac{2}{3} : \frac{1}{2} = 1 : T \]
We can set up the equation:
\[ \frac{2}{3} = \frac{1}{2} \cdot T \]
To solve for \( T \), we can rearrange the equation:
\[ T = \frac{2}{3} \div \frac{1}{2} \]
Dividing by a fraction is equivalent to multiplying by its reciprocal:
\[ T = \frac{2}{3} \cdot \frac{2}{1} \]
Now we calculate \( T \):
\[ T = \frac{2 \cdot 2}{3 \cdot 1} = \frac{4}{3} \]
Thus, it will take Charla \( \frac{4}{3} \) hours to complete the entire picture.
The final answer is:
\[ \boxed{\frac{4}{3}} \]