The former American Idol star met the recently-estranged couple while she was a contestant on the show and Lopez was a mentor.
She said to OK!: 'I met them a couple years ago when I was on, and she was the mentor. I remember meeting both of them. They were both so sweet.'
Sparks said she was saddened to hear news of their split.
She added: 'It's really sad when any marriage ends because you want to see it work, so I hope that they can be amicable.
'I'm sure they still have tons of love for each other and I hope that they are happy - for the kids as well. They can get together and be around with the kids. But I love both of them, and I hope they're both OK.'