Stuart - 16" full grown, 2 yrs old. 75 gall.
Stanley - 15" puberty boy, going on 8 mos old. 55 gall.
Stella - 12" little girl, same age as Stanley. 30 gall. (clutchmates)
I had read that two dragons could be comfortable in a 75. With there being two men and a young lady, there's no question...