Hi!! I have a 19 month old son and a 6 month old daughter. My son is currently in a Britax marathon, daughter is in Chicco carrier. Both of my kiddos are tall and carry their height in their torso. My DH and I are looking into what car seat to buy next. Do we buy a new marathon for my daughter, or do we pass the Marathon onto her and buy him a differant car seat (one that can be used longer) I was looking at the Britax Frontier but it says from 2 yrs old (I anticipate that my daughter will be too tall for her carrier before she is 11 months old)... Any help/suggestion/ideas?? TIA!!