Visitors Visa Extension

Recently we applied for extension of tourist visa for my mother who was visiting us after I had my first child. In the extension application we provided the following reasons for extension: "My daughter gave birth to a baby and I was offering her emotional and physical support to take care of her child and so I couldnt visit places that I wanted to visit."

INS rejected this indicating that the applicant claims that she was taking care of her grandchild for the past 6 months which is illegal employment and she has violated her status as non immigrant visitor. Although the employment identified was with a relative it nonetheless be employment and therefore not be authorized under the visitor for pleasure non immigrant classification" I am very scared at this illegal status statemnet that it might effect my moms future entry to USA. She wasnt doing any employment with me and how can they infer it as employment and state her total stay as illegal which sounds scary. Please help. I am very scared that they will not allow my mom to USA in future though she has 10 yrs multiple entry visa.

My mother was providing me the support that any mother typically provides to her daughters during her motherhood. She wasnt doing any employment. But INS interpreted as employment.
What should I do to clarify this to INS and how can I remove this illegal status mark from my moms records. Please help me. Thanks in advance.