The 33-year-old actress and singer uploaded a sweet Instagram photo of Caussin, 30, with their 1-year-old daughter Jolie, perched on his shoulders.
“We may not have the perfect fairytale love story but what is perfect between us is our little girl,” Kramer wrote.
“Happy Father’s day to Jolie’s daddy. There’s one thing we can for sure always agree on … you’re an amazing father and she’s so lucky to have you.”
The adorable tribute comes nearly a year after news broke that the country star and the former NFL tight end are taking a break.
“This has been difficult for Jana but her priority is being there for Jolie,” a source close to the singer told PEOPLE at the time.
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Kramer and Caussin have seemed to remain friendly since their split. And the former love birds even reunited earlier this year when Kramer threw out the first pitch at a Los Angeles Dodgers’ game, E! News reports.
“He was very nice, cool,” an onlooker at the game told PEOPLE. “They warmed up her arm so she could pitch. She was fun and sweet and seemed happy.”
The source added: “She was very excited to be there and was having fun doing the pitch and wanted to get it over the plate. She killed the pitch, no bounces. And got it right over home plate from the mound.”
In the photo Kramer shared on Sunday, Caussin’s wedding ring was clearly visible. The country singer has also kept her wedding ring on during the couple’s separation, although she did remove her engagement ring.
REPORTING by MELODY CHIU