@morriswalters & KurtinStGeorge
One of my WAGs in the PG thread is that the reason Winter sends all their spare troops to the Summer border instead of attacking the Ramps for trespassing on their territory is that the Nfected Maeve convinced Mab that Lily was the one who was Nfected (probably saying that Nemesis fled from Aurora into her after the former’s death). As a result, Mab starts preparing Molly to become the new Summer Lady (throwaway line at the end of CD about Mher considering Molly a better candidate for Summer).
Perhaps Titania got wind of Mab’s dislike for Lily, and knowing how the Sidhe love symmetry, figured that Harry would be put on the job to remove Lily. As a result, she tries to attack him when justifiable - even if it is proactive perhaps.