All of the above, plus Pine Loop and Limekiln in Brown County. More elevation change, but my girls have been riding them since they were able to ride two wheels.
Every kid is different, but my 8 year old girl had ridden Pine Loop, the North Tower connector, and North Tower, and Limekiln in Brown County, most of the Fort Harison trails, and Mann Loop at Southwestway.
She's definitely more adventurous than most 8 year old girls though.