I've seen conflicting views on this question. This sentence for example: “My people can have assets in place for the middle of March. That’s what? about eight weeks away by my reckoning.” Some say the word after the question mark should start with a capital and others say no. I have another example where the character is thinking to herself: What harm was there in playing a little? she asked herself. If I change the first example and put a capital on about, it sort of interrupts the flow. Thoughts?