Richard Mithoff said Wednesday that the Astros had contacted the family and they wanted representation as the discussion continues.
For the first time, the child's injuries were detailed.
Mithoff said she had a skull fracture, brain edema and an abnormal result on an EEG scan.
"She had one major seizure as she was leaving the hospital the first time, and she had to be returned. She has had episodes where she appears to be staring off and the family is not sure whether those are seizures or not. That's one of the reasons they'll be retesting and reassessing her in the next several weeks. We don't know what the long term effects could be," Mithoff said.
The family requested their name not be made public.
Mithoff said the ball was estimated to be travelling at 100 mph when it hit the child, according to an expert he consulted.
"That gives you a second and a half to respond," he said.
He noted the girl and her family were sitting in field level seats, directly next to an area on the same level that had protective netting across it to protect spectators. He noted several other ballparks have extended netting across larger areas in response to fan injuries during games.
No lawsuit has been filed, Mithoff said.
"I know Jim Crane, and I believe he'll do the right thing," he said.
There is a disclaimer on the back of game tickets that warns fans about the possibility of injuries from foul balls.
"That's a doctrine that's been around for a long time that anticipates part of fan enjoyment is being able to catch a foul ball. Of course, there's a difference between catching a foul ball and shielding yourself from a line drive at 100 miles per hour," Mithoff said.
An Astros spokesperson said the organization had no comment to make at this time.