Il s'agissait d'une ravissante fille à qui il ne manquait qu'un brin de toilette pour paraitre vraiment sensas.
From San-Antonio Chez Les Gones
In terms of translation into English, here is how to parse the French:
- il manque quelque chose dans la maison = something is missing in the house, notice the reversal in English [impersonal usage]
- quelque chose manque à quelqu'un: someone is missing something, also a reversal in English
il manque in French can be impersonal in the sense that il does not refer to a subject. It functions impersonally. So, to translate you take the object or thing that comes after the verb manquer and make that the subject in English.
Here, the young lady was missing a bit of grooming
à qui: of whom, literally, will disappear in English because it is French structure:
X manque à quelqu'un becomes: X [a person] is missing something.
- Il s'agissait d'une ravissante fille à qui il ne manquait qu'un brin de toilette pour paraitre vraiment sensas.
il ne manquait qu'un brin de toilette=
- only a bit of grooming was missing for her to look really sensational.
Note: in English, we don't use groom much anymore due to the negative connotations re child abuse. However, here it does work.
Other verbs: fixing up, tidying up, etc. In other words, her look was not put together. Most likely her hair and nails.
Now the first part: Il s'agissait d'une etc. cannot be translated using the usual: This concerns or this is about, here. So, let's take the ravissante fille and do this:
She was a very beautiful girl who was only missing a bit of grooming (or cleaning up or tidying up etc.) to look really sensational.
She was a very beautiful girl who only needed to be cleaned up a little to look really sensational.
The first shows the process but is a bit awkward; 2) is smoother and the term missing disappears, too.
ravissante could also be: ravishingly beautiful but that is more unusual in English.
A bit of a tidy-up is fine too.
In English, you hear: You clean up well, to mean that a person looks nice when they are dressing up.