How to combine LED and voltage divider
Looks like it should work. You'll have about 8V at Vin, depending on the voltage drop across D1. That's fine since the Arduino's voltage regulator should handle that nicely.

You'll have about 4V at EP, a bit low for a 5V Arduino, but should work. If you have a 3.3V Arduino, that could be a bigger problem.

You'll have about 16.5mA going through the red LED, so if you're using one of the basic 5mm LED they usually have a max current of 20mA and a suggested current of between 16 and 18 mA. So perfect there.

However, if you wanted to use standard resistor values and get your EP voltage closer to 5V, you could do this. The current through the LED would be just over 17 mA, brighter, but still within suggested range.