Yes, since pictures cannot be exchanged that is surely proof that Lena knows her biological Dad, sure!
![Laugh :LOL: :LOL:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Sneaky :sneaky: :sneaky:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Her mother treats Lena like a servant and money sender, nothing else. Her stepdad is the ONLY one in her family treating her decently.
I would be less than surprised if Lena´s Mom did not exchange the pics of Seymour for some random guy, because she knows the moment Lena learns that Seymour is her Dad, the money Lena sends will go away forever.
Just remember that Seymour, no matter his pros and cons, treats Lena vastly better than her family ever did even on the worst playthroughs.