Interact with her through the day. Once you get 10 points of Depravity, whenever you start a new day (don't get out of the bed), pick the option "Spend Day with" and pick Martha, this will complete the day and give you 5 points each time you do. Feel free to repeat the process until you get her at 70 points, as that's the max.
You first need to interact with the Merchant once. Whenever you wake up, dress yourself up and go to the gate outside the house. A hooded figure should be outside. After the MC mentions he has nothing to sell and says something about Doyle, go talk to him and he'll mention something about getting a ring. Then you go to the attic and now you can move it.
First you need her at 70 points of Guilt, and make sure the MC has 70 points of Depravity as well. Complete all of her scenes at least once with the exception of the bathroom handjob, that one you gotta finish twice. After the 2nd time, if you completed all the other scenes with her, she'll mention she's gonna go to her bedroom. Enter the bedroom and you'll have sex with her. The state trigger will happen at midnight, she'll be by the fire place. If you can't get it, replay a couple more of her scenes and try again. For Passionate specifically, choose the 1st option in every moment you can make a choice.