I think BEEM is a girl and not a boy, if you can observe her uniform it has the same design as sylvia's.

That could be true but then again some of the demons don't care for dressing in their assigned uniforms, like how Opera and Kalego had half-and-half uniforms, but I wouldn't mind Beem being a girl since they'd be invited to the next tea party

Hmm, for the characters that could pass up as either guy or girl, I think I’m only convinced they’re a girl if they said it or they become part of the tea party with Clara and the others for girl talk just as the previous commenter said xD

Well they use they/them pronouns so IG they're comfy about being gender fluid or gender neutral ╮(￣▽￣)╭

I think that demons have a very fluid perception of gender and no one really gives a shit in their world