Meaning of "en" in "Elle s'en trouva toute ragaillardie"

Question

The question is on the meaning of "en" as occurring in this quote from Le Petit Chaperon Rouge.*

Ils étaient bien contents tous les trois: le chasseur dépouilla le Loup et l'emporta chez lui. La grand-mère mangea le gâteau et but le vin que le Petit Chaperon Rouge avait apportés. Elle s'en trouva toute ragaillardie. Le Petit Chaperon Rouge cependant pensait: "Je ne quitterai plus jamais mon chemin pour aller me promener dans la forêt, quand ma maman me l'aura interdit."

Is it correct to understand:

(a) That "en" is a reference to the cake and wine.

(b) The sentence containing it means: She found herself wholly cheered up by them (i.e. by the cake and wine).

(c) The sentence can be expanded to: "Elle se trouva toute ragaillardie du gâteau et vin." (Or perhaps "du gâteau et du vin"? I don't know that in French, as in English, you can omit the article from before all but the first item of a list at least when all the items are the same gender.) Thanks.

*For full text, click this link.

Answer 1

La grand-mère mangea le gâteau et but le vin que le Petit Chaperon Rouge avait apportés. Elle s'en trouva toute ragaillardie.

can be melt in one sentence :

La grand-mère se trouva toute ragaillardie d'avoir mangé le gâteau et d'avoir but le vin que le Petit Chaperon Rouge avait apportés.

So, en isn't a reference to the food but :

a) It refers to the fact of eating and drinking

b) You are right, she is cheered up but because she consumes them, not by just their presence.

c) You can't say

Elle se trouva toute ragaillardie du gâteau et vin.

Because you cannot ommit "du" (= "de le").

Grammatically saying the following sentence is right :

Elle se trouva toute ragaillardie du gâteau et du vin.

but is not what we say, we would prefer :

Elle se trouva toute ragaillardie par [le fait de manger] le gâteau et le vin

---

EDIT : To answer to you comment, the previous expression between brackets can be omitted, because the most often thing done with food and beverage is to consume it.

Using "par" rather than "du" give a movement indicating that the satisfaction effect comes from the food and wine. "par" does not implies that it has been eaten but that her granny has been "ragaillardie" because Le Petit Chaperon Rouge brought cake and wine and they could share it to take back colors on her granny's face.