Next time she mentions it say "I know I've got a baby carrot" with a smirk and whilst closing your hand into a fist, apart from your little finger, that you hold out as an imitation of a bent droopy baby carrot.
And then just carry on the conversation, saying whatever you want to say and maybe going off on a tangent. EG "My aunt Esmeralda had an allotment. She used to grow veggies. One year she built a greenhouse..."