I suggest you look at the list of authors on their site and see the quality, and which publishers said author's work has been sold too. You can cross check the author's work on the publishers' sites/amazon/in a book shop if you are so inclined,
Full request: 23/05
Nudged with offer: 29/8
Offered rep: 2/9
In the end I went with a different agency, but I both spoke to Jo on the phone and met her in person, and she was INCREDIBLY nice and enthusiastic - I wouldn't hesitate to recommend her to anyone looking for an agent for YA or kidlit.