The translation goes "Isn't she really gorgeous?" for "how gorgeous can you get, right?" So when you say "can you get", is it an emphasis? What do you mean by can you get?
This construction has plenty of variations: "how stupid can you get?", "how rude can you get?" etc. "He just snatched it out of my hand and walked away, how rude can you get?".
I think the underlying query is: "Is it even possible to get more gorgeous/rude than that?".
not a teacher