actually, according to this link, : The preposition de is used with a name or a noun in place of 's or s' in English. le livre de Jean - John's book la chambre des filles - the girls' room "elle" would be an stressed pronoun, so it's not possible tu use d'elle as you need to use "a" but I find strange to say "il m'offre la nourriture à elle", I'm confused now .... sorry
Actually say something like, Il m'offre sa nourriture à elle for "He offered me her food." Or you could use the object's name instead of the pronoun. Il m'offre la nourriture de Marie. Or, Il m'offre la nourriture de la femme.
In a real life conversation, there would be no confusion. Either the listener would know the object from the context, or could ask the speaker to clarify.