Nitschke made full-time coach of Australia women's cricket team
Nitschke held the job on an interim basis since May when Matthew Mott (48) left to take over as the white-ball coach of the England men's team.
Under Nitschke, Australia won the Commonwealth Games gold in July but face a leadership void with skipper Meg Lanning (30) on indefinite leave and vice-captain Rachael Haynes (35) retiring last week.
With Ellyse Perry (31) and Alyssa Healy (32) also approaching the twilight of their careers, maintaining Australia's global dominance will be a challenge for Nitschke.
"The loss of Rach will no doubt be felt, but it presents a great opportunity for others to put their hands up both from a leadership perspective as well as with the bat and in the field," Nitschke said in a statement issued by Cricket Australia.
"Our challenge is to ensure the team continues to evolve; we've seen teams like India take their game to the next level and it's important that the players feel they have the support they need to keep getting better every day."
The former all-rounder will step down as Perth Scorchers head coach at the end of this season's women's Big Bash League.
"Shelley is an incredibly well-respected coach with a proven track record," CA high performance manager Ben Oliver said.
"She knows what it takes to be successful at an international level and brings significant coaching and playing experience to the role."
Nitschke will begin her tenure with a five-match Twenty20 tour of India in December and oversee their 20-overs World Cup title defence in South Africa next year.