Here's the best I could find for Steven and Stephanie's gargoyle forms.....

Stephanie looks kinda like this ⬇️

But obviously does NOT look like princess jasmine-turned gargoyle....
(Also does not have the piercings....)
She doesn't have wings tho

But she's colored more like this ⬇️

Steven looks kinda sorta like this ⬇️

Buts he's way obviously NOT a female...
he doesn't have the earrings
His tail is longer
His wings are a bit bigger
He doesn't have spike things on his knees
And his skin tone is a bit of a darker grey