But it seems the opposite is true of Dannii, as Rachel recently revealed that she is still offering her support almost seven years after they met on the ITV talent contest.
"If I didn’t do The X Factor, I might not be in Hollyoaks now," Rachel told Inside Soap. "I chatted to Dannii last weekend, and she’s so proud that I’ve bagged such a great role.
"Of course, she’s been in a soap herself (Home And Away), so she’s told me that although it can be busy at times, I need to embrace every moment, and have fun with it."
In a separate chat with Digital Spy, Rachel urged X Factor boss Simon Cowell to get Dannii back on board for its new series.
"She was a great mentor and really got stuck in. I think The X Factor needs that," she said. "They've had some great judges, but I just think they need someone like Dannii who knows her stuff and can really help the contestants out.
"I think keep it to the original four from when I was there - so that was Simon, Cheryl, Louis and Dannii. I don't know if I'm being biased but I just thought they were great."
Unfortunately that won't be happening, as while it's possible we could see Louis and Dannii back this year, Cheryl recently confirmed she is quitting The X Factor to concentrate on her music.
Although we haven't seen Dannii on The X Factor UK since 2010, she has been a panellist on the last three series of the Australian version.
Rachel made her first appearance on Hollyoaks earlier this week after it was announced last month that she'd signed up to play the real Lisa Loveday.