Lennox is in Year 11 at Wanganui Collegiate, while Conder is in Year 13. Collegiate's Alec McNab, also an NZSS executive member, said both made their first world-level appearance with the larger NZ Schools team of 21 athletes in Melbourne last month, as part of the build-up for ISF's event.
Conder is coached by his father Robert, a former New Zealand international, and has the honour of being named as team captain for Hungary.
"Conder is ranked third in the Youth 1500m rankings with less than two-tenths of a second separating the top three," McNab said.
He added Lennox had made "spectacular progress in the sport".
"She stepped up from the under-16s at NZ Schools in Dunedin to bolster the Collegiate team effort, and surprised herself by coming seventh and with it [earned] selection for Australia and Hungary."
Lennox is the daughter of Gillian and Guy Lennox, the former Wanganui Heartland rugby coach.
Robert said his son and Lennox had done some joint fundraising.
"We are hoping to tap into some sort of corporate sponsorship, which would make it all so much easier," Robert said.
Gillian said that, while her daughter had been doing jobs, the serious fundraising would begin when exams finished.
The public can also help out when the hat goes round during a NZ Heartland rugby match at Cooks Gardens on November 13.
McNab aims to set up a 2km road race at Cooks Gardens, featuring Lennox and Conder.
In the meantime, anyone keen to help is welcome.