does she need to lose weight? or just affect body recomp?
she may not be eating enough, she may be eating too much, you're not giving many details.
it's normal for weight to fluctuate during the day and from day-to-day. she should weigh herself in the morning and that's it.
As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.
– Ernest Hemingway