Like her husband, Gertrude never made a physical appearance in the movie but a picture of her can be seen in Jorge Gutierrez's tumblr.
Gertrude was born into a very wealthy German family in Mexico City and was the daughter of a powerful general. Back then, El Capitan Mondragón had been trying to court Carmen (who only had eyes for Carlos), until he met Gertrude.
She didn't have a good relationship with her father, so she agreed to marry Mondragon (a nobody) to spite him . During their marriage, Captain Mondragon grew to love Gertrude with all his heart, but his love wasn't enough for her  and she demanded him to gave her a luxurious lifestyle, which may have resulted in him and the Medal of Everlasting Life.
When Gertrude found out her husband died during a fight with Chakal she knew the reason involved the medal. So she retreated with her daughter Matilda to her mansion in Mexico City crazed with guilt and left Joaquin behind in San Ángel to train with General Posada .
Gertrude has brown hair like Joaquin with some streaks of grey hair done up in a beehive-like hairstyle, brown eyes and pale skin. She wears a long sleeved victorian black dress that hides her feet from view with a long sleeved button up white blouse underneath, a cameo choker necklace and pearl earrings.
She is described as being "frigid and not the most caring".
She is also spoiled and materialistic since she cared more about having a lavished lifestyle than she cared about her husband. However, she did care for Captain Mondragon since she went mad with guilt when he was murdered as she blamed herself for his death due to her greed.
- She was designed by Jorge Gutierrez's wife Sandra Equihua and her design was inspired by an expensive perfume bottle.
- She taught Joaquin how to speak German.