<human>: Provide a brief overview of the text.

Here's how things went down:
I study Aikido, a martial art that is, compared to others, relatively laid-back, peaceful, and harmonious. My dojo has classes for kids, young people (middle and high schoolers basically) and adults. People from the middle and high school classes who have been training for a while are welcome to train with the adults class if they desire.
Yesterday, we were practicing knife takeaways using wooden training knives. I ended up working with a girl who was probably around 14. She was also about a foot and a half shorter and at least a hundred pounds lighter than me (I'm an early-20s guy, about 6'1" 200lbs). While I normally love situations like this, since training with people of a variety of body types can be really useful, it made me really uncomfortable to be, even in a training context, holding a knife on someone (in this case from behind, blade to the throat, about as creepy as a knife hold can get in my experience) who, to my eyes, is a "little girl".
However, it seemed like if I brought it up it might have just been incredibly mortifying for this girl who intentionally came , so I just kinda didn't bring it up and 'suffered' in silence through wondering whether I even should have felt awkward in the first place. Should I have? I'm basically asking what you, had you been in this girl's situation, would have made you most comfortable. I really don't know, and it's been kinda eating at me.
<bot>: was put in a kinda awkward situation in martial arts training with a young girl. Didn't say anything about it to avoid embarrassing her, but still  felt kinda wrong.