How should we write height in a story when the height is either in dialogue or a thought? Verbally we often say someone is five four, leaving out the word foot, but should it be written correctly either as five-foot-four or 5’4″?
People speak in words rather than numerals. That’s why you wouldn’t type, “Dude, I called you 2 times!” into your fictional dialogue. Same thing goes for typing a measurement into dialogue. The height measurement in your example should be spelled out in this manner: “five-feet-four.” For a character with a more casual speaking style, “five-foot-four” or “five-four” will do the job nicely. Since internal thoughts are essentially unspoken dialogue, they get the spell-out treatment, too.