advice needed.

Hi, this is my husbands second marriage, my 3mths baby and me are staying together with his 2 children age 8 and 11. They have a very good helper with them since they were baby, who is taking care of my baby now. However, the helper doesnt really listen to me when I comments about my baby's situation. Eg baby's face always scratch with fingernails.. or excessive crying.. Her reasons: busy with housework n 2 other children. Have asked if needed a part time helper to do chores so as she can focus on infant. She said no and could handle. How would u all address to such situation? Any advice might help :) thanks.