Answer
See the figure below.
Work Step by Step
As we can see in the figure below, we can see the images of the two point objects appearing on the pinhole camera's film, on the left, without overlapping.
Now we need to find the distance between the images of these two objects on the film of the camera.
From the geometry of the second figure below, we can see that the two triangles are similar. So that
$$\dfrac{h}{H}=\dfrac{0.07}{1}$$
Thus,
$$h=\dfrac{7}{100}\times H=0.07\times 2=\color{red}{\bf0.14}\;\rm cm=\color{red}{\bf 1.4}\;\rm mm$$
which is a good distance on the film to distinguish the two objects.
