Groot wished that he did. If he did, he could drag her along and give her back to them if he knew who they were. But he didn't. He knew a lot of people, but not them.
And so he was apparently stuck minding a child until she was either found or got bored of him and wandered away.
He probably shouldn't let her get bored and wander away. That wasn't being a good person. But Groot had trouble caring.