"The queen wants her personal food."
Translation:La reine veut sa nourriture personnelle.
In French, if you say "la reine veut sa propre nourriture personnelle" it sounds redundant (propre and personnelle meaning exactly the same thing).
"Le manger" can be used as baby talk sometimes. Though you can often hear "Le manger est prêt" (my mum says that lol). But it is quite unformal.
Because Duo expects a direct translation: food = nourriture.
But I will repeat myself once again: we don't use "nourriture" as often as Anglos use "food" and really another word would be found in French: repas, aliments would do a better job.