If a fallen angel ever arrived from wherever angels fall; and needed to discover a human soul pure enough to help them return home, they would never carry the physical appearance of the socially defined beautiful woman, sharply dressed gentleman, or even a naive child. By all accounts, they would likely attain the manifestation of a bland, nondescript, lower than average in looks and style, aging male or female; the kind who cannot be forgotten, for they are hardly remembered at all.
The reason is simple; beautiful women are treated like royalty by men, and passively envied by women; guys dance for their acceptance, and women aspire the attainment of their aesthetics; in order for the same men to dance in the same way - unaware it only leaves these women feeling more objectified than before. A man in a suit is instantly perceived as mighty and successful - even though anybody can purchase a suit for as little as thirty pounds; thus affording a possibly of both genders bending to his will. And a naive child is full of the joys and wonder of existence - and every one gravitates to a being who holds the true essence of God inside of them. These are all subconscious acts - mixed in with the evolution of human psychology, and primal notions of our survival instinct; serving the self, not the soul.
A true saint who deserved the knowledge of aiding the angel, would need to be one of the genuine few who help this supposedly worthless person - even in a fashion as minimal as holding a door open for them, saying hello, or wishing they attain a pleasant journey through their day. To do so carries no ulterior motive; it is an act of trying to make another person happy. It can be argued these acts take place to supplement the well-wishers internal being, but this is cynical, and suggests all action is inherently selfish - and there are too many accounts of sacrifice for me to believe it entirely true. And, in silent awareness that social determination dismisses their value as much as it exacerbates the other three, why help them anyway?
This is not to suggest an attractive woman, suited man, or child cannot be angels; by all accounts, discovering the soul within these manifested beings is a different challenge altogether - one where it would take a potentially arduous process of breaking down barriers of psychology, reaching the real person inside, then working an understanding of desires, attributes, and deeper core, and in the child's case, having to tread very carefully so as not to distort their development.
The paradox remains, however, that should the looker or the sharp dresser be true angels, they may become so jaded by the human experience, treating them in a way they know deep down they have done little to deserve, over the unnoticeable strangers of life, or even become seduced by their new human powers of external association - they may eventually forget they were angels at all - leaving them lost for all eternity...