How do I reach the E string with my pinky?

With proper positioning, you can reach the E string with your pinky, even with small hands.

Start by making sure your strap isn’t too low, and try tilting the neck angle up a little.

After that, you could try the "Pinkification Exercise":

-> Straighten all four fretting fingers and reach to the E string with your pinky. The remaining three fingers should extend past the neck.

-> Adjust your elbow and wrist so that you’re as comfortable as possible.

-> Bend your other three fingers to line up on the E string as well.

This will give you your basic position for using all four fingers on the E string: your pinky will be straight, with your other fingers more bent, so they all even out.