egafd.com

Mary B. = Lyvia

Mary B. is only listed for Schrei, wenn Du kannst!
You can see her at the back cover and in the previews for scene 3 and 4 here.

Her name at IAFD is Mary B. and they list her correct for Schrei, wenn du kannst!

Both actresses are indeed the same person but as far as I can tell she was never credited as Lyvia.

In "Sklaven der Lust" jj assigned some of the character names incorrectly.

It should be like this:

Alena S. plays 'Jungstute Monique'
Livia Choice plays 'Boxenluder Lyvia'
Lyvia/Mary B. plays 'Sch?lerin Marie'
Sidney Dark plays 'Lady Yvonne'
Vanessa [20] plays 'Novizin Verona'
XNK5773 plays 'Schlangengirl Vicky'

Since there is no source for the name Lyvia (nor Livya) I suggest to choose Mary B. as new main name.