"Ruggedly handsome Antonio and beautiful Stella del Carmen 1997," she captioned a picture of her husband with their then one-year-old daughter.
"Antonio, Stella and me 1997," she wrote alongside another throwback photo of the trio.
At their time of their surprising separation, Melanie and Antonio alluded to their close friendship by saying their divorce would be carried out in a "loving" and "friendly" way.
"We have thoughtfully and consensually decided to finalize our almost twenty years marriage in a loving and friendly manner honoring and respecting each other, our family and friends and the beautiful time we have spent together - Melanie & Antonio."
Following the split, Antonio has moved on with his new girlfriend Nicole Kimpel, who visited him on the set of his new movie Altamira in October.
Melanie, meanwhile, shared photos of herself with friends as she spent her first Christmas without her husband of 18 years.