Edit: I've added in LifeSuxPlayHalo's comment here as this is what we think the only requirements are for this achievement (original post left unedited below):
After multiple tries and Chrisie81’s guide I believe the only things required is everything that makes Elea speak... here’s everything I clicked on in order:
ELEA’S ROOM: dress near telescope, mirror, get the folic acid from the dresser on the left side of the bed, get coffee mug in bathroom (use mug on faucet to take pills)
***when you walk downstairs the power will go out, go to basement to fix it***
KITCHEN: click on messy sink area, walk over to sofa chair and the broken wine glass will be there, turn around from here and go inside the little bathroom and click on mirror, then pickup Zimone record by the tv and play that (not sure if you have to)
SPA: click on fish mural, pickup moon rock, go into sauna and turn it on and sit down (wait 10 seconds, get up and leave)
GARAGE: click on motorcycle
***walk upstairs to the Study, sit in chair first that’s to the left of the painting***(she technically grunts standing up and I believe you have to do this)
STUDY: code is 4472, use computer to unlock your kid’s room (make sure to hit RB so that you see the picture of the ultrasound), finally accept call from husband
This achievement seems to be an awkward one, I am not 100% certain on the requirements so I cannot give an exact step by step but I can tell you what worked for me. That said I hope my experience can help others figure out what needs to be done to get this and more people can join me in that 100% list
I knew the achievement was achievable in the house before progressing to the next chapter due to the order of achievements of the first gamer who unlocked this, the spa picture also provided that clue.
I started a new game (may have been my third new game) and set about interacting with all the items in the house. After turning on the generator I went around every room, clicked on everything, opened all possible cupboards, turned on the lights, mirrors etc. Eventually I got bored after about an hour and decided to move on, the achievement popped when I interacted with the computer in the study.
I do not have a full list of all items but I have included a room list below with some notes. If someone else wants to provide the full list feel free.
List of rooms - remember interact with everything, this is not a full list!
Babies room: there are also toys in the cot I missed first time around. Also build the furniture (cot & cupboard) as this is a separate achievement and interact with both.
Bathroom: opposite babies room, a couple of cupboards and items including a mirror.
Parents room: Plenty of cupboards, also ensuite bathroom. There is also the folic acid pills in the left bedside cabinet, use the cup in the bathroom to take these - it might count.
Open plan kitchen/dining/living room: absolutely loads of items, go around everything! Including putting the record on the player, interact with the 2 tvs, some odd shaped lights on the cabinets etc (this will take a while).
Basement: I missed the cupboards first time.
Garage: nothing special jumps out here but I missed the toolbox by the bike on the floor previously.
Spa: Also obtain the sauna achievement here. There is also a gym. And I missed the little item on the pedestal which also has a comment related to it, this is where the picture of the fish is on the right as you walk in.
Upstairs landing: chair to sit in, tv, cupboards etc
Study: various items on desk, solar system display, next to cabinet that lights up when you click on it.
Of course you may only need to do a much smaller list of things for this to work but until more gamers have unlocked the achievement this cannot be confirmed. If anyone unlocks it without interacting with everything please comment so I can update the guide.