The title of this short means “One Too Many.”
The film opens with a wife walking out on her husband and their (teenage or young adult) son.
Shortly thereafter, the father and son go to the old folks home and get her mother and bring her home to live with them. Why is not explained, though the apparent reason is just that they want someone to cook for them and to handle all the housewife-type functions. There’s also an indication later that it might be intended as a way to entice the wife back. No reason was given for her departure, but evidently one thing they clashed about was putting her mother in a home to begin with.
Other than the rather disturbing fact that the husband and the son show zero emotion concerning the wife or her mother except insofar as it relates to their usefulness in doing the cooking and housework, Éramos pocos is a mildly interesting story, with a cute ending.