After Jan worries about having to make new friends if they have to move to a new town:
Marcia: But Jan, you don't have any friends.
After Grandma finally makes Jan's psychotic inner voices go away by acknowledging her, the inner voices are passed on to Cindy.
How Grandma makes Jan's voices leave in the first place:
Grandma: Jan, cut the crap!
From the sequel, when Roy/Trevor and Carol arrive in Hawaii, the travel agent tells them they're very open-minded on the Islands, and have liberal policies regarding gay people; Carol, stuck in the 70s, takes the term "gay" as happy:
Carol: I wish I could be gay again... and I would be if I was with Marcia... and Jan... and Cindy...
Roy/Trevor: And Alice.
Carol: And Alice?
Marcia Brady: (in Jan's thought) But Jan, you don't have friends. You're just jealous Jan.
Jan wakes up, holds a pair of scissors like a knife, and starts to cut Marcia's hair
Cindy Brady: Jan, what are you doing?
Jan Brady: Go back to sleep Cindy!
Cindy Brady: Jan don't. Marcia's hair is so beautiful.
Jan Brady: Exactly. That's why I'm gonna make alot of money when I sell it.
Jan continues to cut Marcia's hair and laughs psychotically then Cindy screams followed by Carol and Alice coming into the room
Carol Brady: Jan, what are you doing?
Marcia's got a new hairdo
Carol Brady: Oh Marcia, I love your hair!
Alice: What a groovy hairdo!
Cindy Brady: Oh, you're so beautiful!
Jan Brady: No! She was supposed to look bad! No! No!