You didn’t head off the question as to why you didn’t just pick it up. It looks your delivery costs were a whopping 28% of the total. If you ain’t cooking, you’ve probably got the time to drive. Or better yet walk or bike (obviously only if it’s close enough).
But that being said, I recommend always considering getting a large pie. Remember, the area grows with r^2^
So for 6 extra dollars (to get the 16 inch) you get the equivalent of 2.5 10" pizzas. And you have some leftovers. Granted this doesn’t make sense if no one else is going to eat it but her, but even going to a medium, you get almost an extra half pizza for 2 dollars. That probably would buy at least a second meal out of it for her.