The first season of Ahsoka is deeply connected to Star Wars Rebels, and two of the live-action debuts fans were most excited to see were the debuts of Hera Syndulla and her son Jacen. The epilogue to Star Wars Rebels first introduces Jacen as Spectre 7, the newest member of the Ghost Crew family. Then, Ahsoka Season 1, Episode 5, "Part Five: Shadow Warrior" confirms that Jacen is Force-sensitive because he is Kanan Jarrus' son.
Source：https://www.cbr.com/ahsoka-kanan-hera-conceive-jacen/
