Maria raised her arms in the air after securing victory and rushed over to celebrate with her husband and eldest daughter Charlotte, while youngest daughter Cecilia slept on in her pram.
She took two maternity breaks from the WTA Tour and reached the Wimbledon semi-finals in 2022, just one year after the birth of her youngest daughter.
Her family travel on tour with her, with husband Charles-Edouard her coach and Charlotte a frequent fixture on the practice courts.
Her message after shocking former Wimbledon champion Elena Rybakina in the quarter-finals was to "never give up".
She delivered that same motto again on Saturday after making relatively light work of world number eight Keys.
Keys, one of the in-form players on the WTA Tour, has won three grass-court titles on British soil but was left frustrated by Maria's slice-heavy style.
Maria immediately put Keys' huge serve under pressure, finding the breakthrough in the fourth game before securing the opening set in confident style.
The pair could barely be separated in a tight second set, with both saving break points before Maria sent it to a tie-break.
But unforced errors from Keys gifted Maria four match points, and she took her second as the American missed a swipe at the net.
Maria wrote "OMG finals" with a smiley face on the camera lens after her triumph, before telling the crowd: "I cannot believe it, it's a dream come true.
"I could not wish for a better tournament to be in the final and I'm so proud."
"I love to be here with my family, my team. It makes it so special that we live this dream together."