Then make the 1 skillcheck hard.
Demanding several different skillchecks is what I would call a rookie mistake or vindictive GMing in a tabletop situation.
1 check for initial success - fine. Several checks after that to succed more or get additional information - fine.
Several checks to succed at all - not good.
This, this, this, and THIS.
Nothing changes between the skill checks you have to make with Nettie, it's just:
Nettie: "No."
*Indimidation check successful*
Nettie: "Still no!"
*Indimidation check successful*
Nettie: "Nope not happening"
*Indimidation check successful*
Nettie: "Hmmmm gonna go with no"
*Indimidation check successful*
Nettie: "Ohhhhhh alright."
It's bad GMing in so many ways. It's repetitive, goes against the rules of the game, makes it feel like your dice rolls don't mean anything, and frustrating as hell if you fail on the fourth check. No halfway competent GM would ever do this to their players.