Stuck on Episode 3

I'm at the part where it says to talk to Susan about Allison, and so I go up to her and Julie in her yard, but it won't let me talk to her at all. I can talk to Julie, I can listen to them talk, but I can't talk to Susan. I've done everything else, but I just can't get past this. Help?

And what's with all the carrots? What do they need such good eyesight for anyway?