What about the ADULTS that were accompanying the child? Its was pretty cold and weathery on Tuesday.
How old was the child? Where were they attacked? In the woodedness or in the neighborhood or their back yard? Time of day? A Very incomplete story.
A mountain lion doesn’t know the differentiate when its hungry, between a doe & fawn or any other species. Incomplete story.

Banes:

"The California Department of Fish and Wildlife is actively investigating the incident." That usually means they don't have the info you would like.