In the first season of Full Metal Panic, Tessa tells Chidori about her brother, who is a Whispered. In the second season (TSR), Chidori comes across Tessa's brother Leonard. When Sagara is talking to Gauron in the second season, Gauron comments that Amalgam has a Whispered in their highest ranks and we see shots of Leonard.
I am wondering, just how much does Tessa know about her brother? Does she know that he is working for Amalgam? And if not, where did she believe he was all this time?
In Episode 10 of FMP, Tessa discusses her feelings of inferiority vis a vis her brother. In the light novel series, it is explained that she is extremely aware of both Leonard's past and that he is working for an enemy organization. E.g. in "Continuing On My Own" he openly battles the Arbalest in the middle of the city and captures Kaname from Sousuke. And for the final showdown between Sousuke and Leonard in the final book, Tessa gives him some words to shout to Leonard at a critical time, revealing to Leonard the extent to which she knows about their family history and his subsequent deeds, distracting and demoralizing Leonard, giving Sousuke the chance to land a killer blow.
