The brunette beauty - who turned 40 in November - has revealed she intends to have plenty of fun over the next decade, and she doesn't plan to shy away from the cameras anytime soon.
Kelly shared: "I was dirty in my thirties, I'm naughty in my forties and I'm going to be fit as f*** in my fifties."
The model remains determined to stay in shape, and although she now experiences more aches and pains, she doesn't want to rewind to being 20.
She told The Sun on Sunday newspaper: "Obviously it's still important for me to look as good as I can.
"When you're younger everything is a bit easier, isn't it? But now in the morning when I wake up, my lower back hurts a little bit.
"It really hurts in the morning and I need a good walk and a stretch to get going. Honestly, my back kills me.
"I do miss being able to bounce around and not ache and feel pain when I go to the gym, but I wouldn't want to be 20 again, no way."
Kelly also thinks she's a "better person" for having experienced some "real hardships" in her life.
She said: "I've lost a parent to cancer. I've had a miscarriage. I've been publicly sacked and I was even burgled a few weeks ago.
"But those moments make you a better person because you have more empathy for people - because you've been there and you've experienced it.
"From the moment I lost my dad I really realised how precious life is. It's not a guarantee that we're going to live to be old, it's a privilege if you do. My dad was only 57 when he died.
"He wasn't an old man. He was still working as a scaffolder and I realised - and I know it's a cliche - but you really have to live every day and really try to be in the present, and just enjoy life."