If you look under the thread on Project xmas it will talk about Lauren being adopted etc and this is not the first theory on project xmas either it is posted under season 4 as well. I think........
1. nadia, syd , lauren are the three missing names on will's list for project xmas I am sure of this for some odd reason !
2. Lauren's name at birth was julia thorne and the senator adopted her for a specific reason as part of the trust, yes she is adopted , and when Syd was conditioned by the covenant they showed her videos of the blonde girl etc so that she would know everything about the person's identity why wopuld they do this and at the same time send "Lauren" into marry Vaughn
3. Lauren had a specifc vengenece perhaps nadia is Syd's sis is Irina and Lauren is her sister too via Jack ( yuk)
4. I agree that Bill Vaughn had a great deal to do woth all of it
5. Lauren's mom is the third derevko sister (Irina, Katya and ?)
6. Vaughn was brainwashed, programmed , something to get him hooked on Lauren so quick, he had no emotion when he found Syd that was too odd from the get go
7. Jack is not evil he just did all of this to protect syd and was totally unethical in doing so...........he manipulated agreat deal of her life and has at times worked with Sloane yes, but to what degree I have no clue ?