Answer: Cariñosa/o.
Step-by-step explanation:
Depends on if you mean this as an adjective:
She is the most caring person I know. (Ella es la persona más cariñosa que conozco.)
Or as a gerund:
She is caring for him. (Ella lo está cuidando.)
As an adjective, it may depend on the way you mean it, but probably bondadoso if you mean generous and helpful, or afectuoso/cariñoso if you mean like you would care for your child.
As a gerund, it’s the -ando form of the verb cuidar, so you end up with cuidando.