Males : A, B, C, D, E, F, G, J, L, M, N, O, Q, R, S, T (shark pony), U, X, Z (alicorn)
Females : P, W (twin sisters), Y
Non-Binaries : H, I, K (bug pony), V
Bonus based on [true lore](https://mymodernmet.com/wp/wp-content/uploads/2019/01/history-of-the-alphabet-usefulcharts-thumbnail.jpg), [or this](https://www.reddit.com/r/alphabetfriends/comments/y3kzg7/alphabet_lore_evolution/): A, B, C and G are brothers (G called his brother for CAB) D and E are brothers (that is why they are together whole time) F, U, V, W and Y are siblings (and the reason why ||F did not hurt U, V, W and Y||) H, I (the letter) and J are siblings (H is the only one cannot shoot cannon of the three) K, L, M and N are siblings (K was mutated I think, differ from their brothers) O and P are siblings (P the nicer sister, seems to be unaware her brother is ||not a nice one||) Q, R, S, T are brothers (bunch of mutated species, except R) X is the only child Z is the only child and a god
PS: L here is not from Death Note, N here is not from Pokemon, Q here is not from Star Trek, X here is not from Megaman X