The teenager was part of Tulisa's girls group on the ninth series of the ITV show back in 2012, finishing in sixth place despite being widely tipped to make it all the way.
And, although the show is now over, she's remained friendly with her N-Dubz mentor Tulisa.
"We're still in touch and Tulisa is really proud of everything I've achieved so far," she told Daily Star.
"I actually got a bunch of flowers from her when I got a number one with 'Ghost'. That was so lovely of her."
As well as lavishing praise on Tulisa, the star also spoke about her former X Factor colleague James Arthur, who won her series.
James has enjoyed chart success but also negative publicity in the past two years – something which Ella said she couldn't really comment on.
Describing him as a "big brother" during her time on X Factor, she added: "You hear of things that have happened since. I don't really have an opinion on it because I don't know the person he is now."
After leaving X Factor, teenager Ella stepped out of the limelight and spent two years writing music for her debut album, which is due this month.
One of those songs was the incredible 'Ghost' which has already been a smash hit in the UK. She recently headed to America to promote it there, including a performance on highly rated breakfast show Good Morning America.
Watch Ella's video for 'Ghost' below: