I'm wondering if anyone has experience with lead line showing, and could help me work out what saddle i need!?

My 4 year old daughter has been riding for a few years in my old stock saddle. But I think its time she got her own! I have found a nice 12 inch suede saddle for sale, but wont get to try it out before i buy. Is 12 inches way too small for a 4 year old? 14 inch seems large to me. Anyone got there child riding in a 12 inch english saddle?