Looking at beefing the windows up on my new shed as well (I didnt want a window installed, she did lol).
Already got a bolted in hasp and stable with good quality squire padlock.
Just coach bolted the hinges and installed enfield garage door bolts.
Thinking of getting some MS flat bar with a hole either end and using a good length woodscrew screw at least 2 across each window pane.
No window would have been better, but I was overuled.