Hi everyone. My 3 1/2 year old is just 30 pounds, although pretty tall. I currently have her in a Britax Boulevard. Her little sister is almost 4 months old, and 13 pounds. I would like to move her out of her infant seat soon. Initially the plan was to get older dd a frontier 85 so I could still harnesss her and then put the baby in her boulevard. Does that sound like a good plan, or should I get little dd her own boulevard and leave older dd in hers for awhile yet? I want to do what is safest for both of them, obviously. Thanks for any help.