Nauti might work. My dn is 50 pounds and almost even with the second slots down on the Regent, so maybe not. She told me today that she got my other sister's Radian installed in that same spot. She said her seat was where she wanted it and everything. And of course there was plenty of side to side room. But I'm thinking it wasn't reclined to a 45 needed for a newbie. Maybe, maybe she could do Radian in center for newbie, and put the Marathon behind her. She doesn't want her 6 year old behind her kicking her, center doesn't have TT, and she has to be dropped off at school, so passenger side is best for her. Or even Radian center for 3 yo and infant seat behind her, later the Marathon. Hmmmm...brainstorming outloud helps!!
But in case she can't come up with the money for a Radian....do you think an Avenue, Tribute, or Scenera would work there for a newbie? Coccoro would for sure, right?