Hmmm, 13th chords, very unlucky number, I try to stay away from them. But we'll take a look, what the poppycocks.

G13 = G, B, D, F, A, C, E.

Maj. 3rd, P5, min.7th, 9th, 11th, and 13th. wa la, I have a hard time believing you couldn't figure that out yourself.