How old was your LO when you used the stroller without the Car seat? I mean I know she's too little…

How old was your LO when you used the stroller without the Car seat? I mean I know she's too little to sit up in the stroller, but I'm thinking of reclining it back and letting her lay in it. We're going to Coney Island tomorrow and I'm bringing the stroller and the baby carrier but I just didn't know if I should just keep her in the car seat or attempt to let her lay down in the stroller...