In her defense--no, there is no defense for her. It's not like the Texas Rangers are infamous for throwing back opposing home run balls (the dinger in question was hit by Chicago's Adam Dunn) like at Wrigley Field. Even then, I think Cubbies might even let a little kid keep a ball his Dad gave to him.
All was not lost though. In the end the young Ranger fan was able to leave the park happy (with a few souvenirs)--and allowed not to like his sister for a day.
[The video does work at this link to USAToday Sports.]