[3] Tornaghi finished fourth at the 2018 Italian Championships behind Lucrezia Beccari, Lara Naki Gutmann, and Marina Piredda, after winning silver for the past two seasons.

Tornaghi then finished sixth at 2018 Golden Bear of Zagreb and won silver medals at the 2018 Inge Solar Memorial–Alpen Trophy and the 2018 Christmas Cup.

In her senior international debut, she placed fourth at 2019 CS Ice Star after a free skate comeback from twelfth in the short program.

[5] Tornaghi won her first senior title and international medal at 2019 Golden Bear of Zagreb after becoming the first Italian lady since Carolina Kostner to successfully complete a triple lutz-triple toe loop combination in the short program.

[7] Tornaghi won the gold medal for a second consecutive season at the 2020 Italian Championships, this time ahead of Marina Piredda and Lara Naki Gutmann.

[12] Tornaghi was scheduled to make her senior Grand Prix debut at the 2020 Internationaux de France, but the event was cancelled as a result of the pandemic.

Tornaghi switched her training location to Norwood, Massachusetts, with Alexei Letov and Olga Ganicheva.