It’s a strange use, as I think she must had used the word pitou (pit-tow)
Which could be based off as pitounne, that can be used as a word to describe a beautiful women in Quebecois, but not her intimate part.
A note for pitou, if you check a dictionnary it would refer a synonym of the word dog, but in a slang use, in example a bar in Quebec, You could ...
The word must have been pissou.
Pissou is a colloquial word for a "wee", a "tinkle", mostly used with children. (From the French pisse → pee).
But it is also used to designate the genital parts, male and female (wiktionnaire). Not very commonly used that way though in France nowadays (I don't know about Québec).
In this sentence it is used in a book ...