I'm not so sure about that, if you give her the real potion she makes a point of telling you that she is using it only with you, but IIRC that dialogue doesn't happen if you give her the fake potion, suggesting she knows exactly what you did.Jenny never knows whether the MC has given her a real or a fake potion....
I don't think Jenny cares, the MC is more attractive than her husband, Personally I think she is using babies as an excuse to fuck the MCwill jenny ever find out the child is mc if mc give her fake potion & impregnated her himself?