@Carlo S
I followed your walkthrough for v.7 and on day 20 can not enter sisters room.
"Day 20: Nook -> hug her, chat, ask her about, show her the edited recording, compliment her, leg muscles, where, that's not enough, move shorts down, stop it, maybe we can so something else, hot tub, let's play
Pool -> move umbrella
Your Sister's Room -> go inside and hide her things, carry on, click drawer on the left
Toilet -> shower
Toilet -> clean the yard, do it
Toilet -> clean the yard
Kitchen -> Splash her with water
Storage Room -> tamper with AC, tamper with electricity
Living Room -> check her out, leather suit, follow her, stay, stay, enough
Parents Room -> check cams, watch recorded
Your Room -> get some experience, relax
Nook -> look for some porn
Toilet -> let her win
Your Room -> relax 1 hour"