Finding the Aegrus compound is not easy, nor is it wise unless you have some sort of deathwish. Imagine coming, uninvited, to the very much hidden compound of a very secretive 'race' of people who's very existance is usually subject to question daily and, if people knew they actually did exist, would then be subjected often to blind hate by most of the galaxy.
The Aegrus know where most everything is. An Aegrus doesn't necessarily even look different from your average person. In fact, you could have several Aegrus working for you just to keep tabs on your actions and thoughts. Nothing more.
The Aegrus like to watch people and to study them. It's become a hobby over the centuries they've been separated from the "normal" populace.
Few find the Aegrus. So far, none have lived long enough to even know why they died. Do not try to find them. They will find you if there is need.
Oh, and don't think that fighting a blazingly pitched battle over a few years which might eventually end in your victory will end then and there. You probably will destroy the compound and end a few Aegrus lives. The rest would probably devour your empire from the inside out in revenge.
Lamia, however, is a different story. She is, by now at least, rather well known. Or she should be. In the 100 year gap she wasn't just toddling about, never straying more than a few sectors from her home... No. She's been to galactic center more than once in that time, and sometimes just for things like some exotic technology or ancient relic to a drink or two and a chat with some non-Aegrus contacts she has making sure that she knows of any trouble. Several pirate raids were never even known about because of her actions and love of blasting large holes clean through pirate ships.
By now, I'd imagine that the general populace of the galaxy has well over a thousand different rumors about her, and scores upon legions of stories, legends, and myths involving her. Some likely well over two or three centuries old. She doesn't keep a low profile unless absolutely necessary.