Both are just fine.
I lovee both!!
I think Dragons are for the most part genderless we are the ones with that duality choosing for them :) you give it whatever name you feel like, its fine.
And that is an awesome house to choose!! A cup and metallic!! I hope he is taking advantage of it and asking it to charge whatever he pours in it 
If your friend is on Patreon remind him to fill that cup with water and play the Infrared Plasma Drink Charger and ask the Dragon to learn that energy so he can ask him to replicate it for any other drink he puts in it but cant play the audio at the time. But let him do that several times until it finally integrates and gets familiar to that energy (im talking about the Dragon getting familiar with the audio)
And also check this post for more water releated fields etc