I know that the foal is on it's way regardless, but have you though about testing Lena for LWO? I understand that there is nothing you can do now if she is positive, but it might be best to be informed and prepared just in case if you know what I mean?
She has at least one other white pattern, since currently leanings are toward tobiano not causing face white. Frame can and does hide, so I personally would recommend testing any horse in a breed that has it.
These two horses carry frame, but present a phenotype that does not suggest it (aside from blue eyes, which can also be caused by splash).
This tobiano also carries frame, and as you can see, there is not much evidence of it.
I am not at all suggesting that Lena carries frame. I just naturally suspect any Paint of carrying it, and would always suggest testing before breeding in any breed that is known to have frame.
Known Breeds to have Frame (test based)
American Paint Horse
American Quarter Horse
American Indian Horse
American Shetland Pony
Spotted Kentucky Mountain Saddle Horse
Spotted Saddle horse
Tennessee Walking Horse
Suspect Breeds (phenotype)
Australian Draught Horse
Australian Stock Horse
Missouri Fox Trotter
National Show Horse
ETA: I know you didn't breed Lena, so please don't take this as an attack or anything like that