Ardiente Secreto (1978)

The orphan Mariana Cisneros was shut in (in a college) by an aunt who hates her, she suffers from some terrible pains, but she take advantage of the education and culture. When she turns 18 she finds a job as a governess of a silent and lonely child, Adela, who is the daughter of Eduardo. Mariana wins Adela's love and she is attracted by Eduardo. Mariana and Eduardo fall in love, but a terrible secret will take them apart. She discovers it on the day of their marriage. Mariana is desperate and she escapes, but for love she will return again.