I thought the mom was a good actor in her recurring role on LOST, and I still felt it transferring over to this show... (I imagine that was part of the reason Jorge Garcia appeared on the Talking Dead... and one of them brought up bath salts there)
at one point riding in the car with her daughter, she calls her on her actually caring a great deal about her brother while pretending really hard not to. Then we see the jello scene. But yeah, weird moment of sexual chemistry there.