There. Done.
As far as Garstan is concerned, he has now fulfilled his responsibility by informing the lady's family about the possibility of her goin' a-courtin'. Any additional questions might be answered by referring Farahil to Lin since my poor confused stoneshaper feels out of place and doesn't really know what he should or shouldn't say.
And he'll be on his way to find the children again. Garstan doesn't know what to think of having another Dundendling around just yet after the horse-thieving question with Manawyth (which also puzzles him greatly), but he's inclined to be favorably disposed toward the family. Cnebba made a good impression.
And at any rate, he will follow the Eorl's lead about anyone in the household.