To determine how many heads high the woman in the drawing is, you would typically measure the total height of the figure and divide it by the height of the head. A common measurement for human figures in art is that a well-proportioned adult figure is about 7.5 to 8 heads tall.
If you're provided with specific options like 3, 5, 7, or 8 heads high, and if the figure appears to be well-proportioned, it is likely either 7 or 8 heads high. However, without seeing the actual drawing, it's difficult to give a definitive answer.
If you have the drawing handy, you can measure and count the number of head lengths in total height to choose the most accurate option among those given.