I thought it may have been the girl, but she says it was the wife. They looked alike though! You want it one way, but it's the other. It's the wife and since performing abortions are in her wheelhouse, maybe placing her hand on Vivian's stomach was thinking, "I can't wait to get to that fetus!" Plus she was all admiring the house. Remember her husband built that house specifically for her. She loved the house, just hated she only had two servants to help her take care of it. She's part of the 1%.

>We could be wrong since her and the wife looked uncannily
>alike (was that on purpose?), but that last scene with her
>holding her hand over Viv's stomach kinda reinforced that...
>as if she were regretting going in for an abortion.
>
>Although, if she were the wife it would explain more why she
>was so invested in how the house looked...