If you put it that way, she'll lose face (lit. "her face won't be able to come down").
Tips
usage
Two senses: (1) literal — can't physically get down (off a tree, stage, etc.); (2) idiomatic, with 脸 (face): 脸上下不来 / 下不来台 means "can't save face, embarrassed in front of others." The figurative use is the more common and more useful one to memorize.
grammar
Standard potential complement form: 下 (down) + 不 (negation) + 来 (come) — "unable to come down." Affirmative is 下得来 (xiàdélái, "can come down"), and the simple action is 下来 (xiàlái, "to come down").
