The former Coronation Street star had to sit out of Saturday's show after fainting twice during rehearsals.
But she has confirmed that she is feeling "much better" and will perform with partner Artem Chigvintsev at Blackpool's Tower Ballroom this weekend.
"Thrilled to say I've been declared fit to dance this Saturday," the 29-year-old tweeted. "Bring on Blackpool! I have rested well and I'm feeling fantastic."
Speaking to Strictly's spin-off show It Takes Two about being back in action, Natalie explained, "I felt very weak all week — I think it was just exhaustion — and basically my body just gave way.
"I had had enough, not enough rest or eating cake on the sofa," she added. "So I collapsed unfortunately, and after trying again in dress rehearsals, I realised I wasn't fit enough to dance and collapsed again."
Natalie went on to apologise to her fans for "scaring them", and confirmed she was feeling "much much better".
The show's co-presenter Tess Daly, meanwhile, said she was shocked to witness the actress's collapse.
"When she fainted during the dress rehearsal, I was seated only a few feet away and it was actually really shocking to witness," she wrote on her Yahoo blog. "She was dancing full pelt during an incredibly energetic jive at the time.
"She literally collapsed in a help, legs twisted the wrong way under her, with her head thrown right back and her eyes rolling. Luckily, her professional partner Artem was on hand, quick as a flash, to catch her and break her fall."
At the time, Artem said of the incident, "She was shaking a lot and crying. I am just gutted for her. She is doing such a great job and I just want to say 'Please get better.'"
Natalie is currently one of the favorites to win the dancing competition. Strictly drew its biggest audience of the series so far last week, with an average of 10 million tuning in on Saturday — maintaining its lead over the ITV rival The X Factor, which drew 7.9 million viewers.