Elaine has said very little that is clear, because to say at the same time that she has no intention of following the conditions, which would take her away from MC again, and that if MC should not inherit anything she will take care of giving him his share is quite contradictory.
And also when she asks him to leave her the house anyway, she is clearly referring to something she cannot tell him (Mc thinks about the conditions of the will, and I think so too, but it could be something else).
so Elaine by definition is not a red herring, she's an heiress like MC, who's working hard to get her share (following the will or not) what we don't know is if her benevolence towards him is really sincere. in my opinion there are no characters really antagonistic to MC, but it's my opinion not written in stone
then, I repeat, in Jenna's hacking we discover that the house has to do with the conditions of the will, she asks MC to have the house anyway and that she can't tell him everything, it doesn't seem to me that there is to make particularly elaborate deductions