Christiansen said she thought her "World Cup dream was over" with the injury setback but is now mentally fresh and inching towards a swift return.
"It's been physically and mentally challenging," Christiansen told the BBC.
"Until you get the timeframe of the injury and a plan, then you're left with wondering what's going to happen.
"I had a fibula fracture and some ligament damage and fortunately I didn't have to have surgery on the ligaments. I've been very diligent with my rehab the last six weeks."
Christiansen now hopes to be drafted in Phil Neville's England squad for the World Cup in France, which begins on June 7.
The Lionesses are among the favourites to win the tournament after surging up to third in the FIFA rankings last month, courtesy a string of impressive results to lift the SheBelieves Cup ahead of hosts and world champions the United States.
Neville is aiming to name his World Cup squad before England face Denmark in a warm-up fixture on May 25 and New Zealand on June 1.
"Phil has checked in on me a few times and has been getting messages from my physios and videos of me running," Christiansen added.
"I've still got six or seven weeks to play with and improve my fitness. I need to let go of the fear that I'm not quite 100 percent fit and crack on."
(Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge)
