This picture was taken about 1912.  (The youngest boy, Harry, was born August 7, 1911) 

 I recognize my Grandma Ann right away on the far right.

Standing left to right (back of the picture says Andy Engel's sister, I don't think he had a sister that age and it could very well be Pearl Mabel Anderson and then Carrie Alice Anderson), Mae Finucane, Carrie Alice Jacobson Antonini, Joe Antonini, Mabel Florence Jacobson Engel, Anna Finucane.

Sitting left to right: Mildred Jacobson, Charles Engel, Andy Engel, Harry Engel and Caroline Erickson Engel.

You can see the family tree at https://familysearch.org/tree/

I find this picture quite entertaining.  I love Grandma's (19-year-old Anna Finucane) happy smile.  I wonder about the tension at the moment of the picture being taken between married couple Aunt Mabel and Uncle Andy.  His mother seems quite content.  I wonder where in the Chicago environs this was taken.  What does the sign say on the tree?  Lillian Finucane is missing.  Perhaps she was spending the summer in Gann Valley with her father? 4-year-old Mildred Jacobson is in the picture so why not her sister 6-year-old Florence?  14-year-old Pearl Anderson is in the picture, then why not her sister, 16-year-old Carrie Alice Anderson?