Dr. Maria is Hazel Grace's doctor at Children's. She is first mentioned when Augustus Waters surprises Hazel by getting them a trip to Amsterdam. Mrs. Lancaster decides to talk to Dr. Maria to see if Hazel Grace should be allowed to go or not. Dr. Maria says she must go with an adult, either Mrs. Lancaster or herself.
Postponing the trip is an incident that lands Hazel Grace in the ICU at Children's, where she stays for a few days before Dr. Maria "sniffs her around for a minute" and tells her she can go home. Dr. Maria is liked by Hazel because she is always honest, and doesn't "sugarcoat" things.
Dr. Maria has been Hazels doctor since the lung cancer has started. She is mentioned during the time Hazel went into the hospital before Amsterdam. Dr. Maria is played by Ana Dela Cruz in The Faults in our Stars movie.