Cassie Clare talks new shadowhunter series called 'TLH'

Today Cassie took to Twitter to answer some fan questions about another upcoming Shadowhunter series set in 1903, after The Infernal Devices. Cassie kept mum about the title no matter how many times she was asked. She refers to the three book series by it's initials, TLH

RT @danniecresta: " the descendants trilogy?;) have you already decided what you're calling them?" yep! 3 books, set around 1903.
— Cassandra Clare (@cassieclare) March 27, 2013

RT @freakingcalie: " do characters from infernal make appearances in the 1903 bks?" they would be adults..it would be about their kids.
— Cassandra Clare (@cassieclare) March 27, 2013

RT @citysince1234: " so is the order of the books TiD, the 1903 books, TMI?" then TDA. You can call the 1903 books TLH. :)
— Cassandra Clare (@cassieclare) March 27, 2013

RT @cityoffandoms: " can you tell us what TLH stands for?" not yet. :)
— Cassandra Clare (@cassieclare) March 27, 2013

RT @ohpandabear: " have you already written something about LTH?" I have outlines, and some f the characters are in the Bane Chronicles
— Cassandra Clare (@cassieclare) March 27, 2013

RT @tasshadowhunter: " How old are you planning on making the main characters in TLH?" 16, 17.
— Cassandra Clare (@cassieclare) March 27, 2013

RT @xhungagayums: " are TLH and the 1900's shadowhunter series the same? i feel like i'm missing out on something" The same.
— Cassandra Clare (@cassieclare) March 27, 2013

What do you think TLH stands for? share your thoughts about this series as well as the possible series title