Campton placed sixth in the under-18 years 4km but was fourth of the age-eligible contenders in the gruelling race.
The Byron Bay High student started swiftly to clear the 100-strong field on a muddy Symmons Plains circuit beside the V8 raceway outside Launceston.
Though passed by eventual winner Laura Stacey, Campton trudged to the finish in 15mins 13secs, just five seconds outside the medals.
School Sport Australia will make an announcement about the team tomorrow. Campton's training partner at Tweed Border Striders Mackenzey Ormiston replicated her 2012 result with a silver medal in the 11years 3km championship.
The Ocean Shores sprite clung to defending champion Eliza Rixon throughout to miss gold by just two seconds (11.36).
The squad's Cara Feain-Ryan (Woodlawn College), 14, had an impressive national debut when she placed seventh in the under-16yrs 4km (15.22).
Brianna Campton, the state 12yrs champion, also starred racing up an age with a creditable 13th in the under-14yrs 3km (11.39)
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