's taking a break from his legal issues to support as she lays her mother to rest in Florida.

The former prez stood somber Friday morning next to his wife and their son -- the whole family was dressed in Black as they attended the funeral for Amalija Knavs in Palm Beach.

Melania's dad Viktor remained glued to her side as they followed the casket out of the Episcopal Church of Bethesda-by-the-Sea, ready to lay Amalija in her final resting place.

It is with deep sadness that I announce the passing of my beloved mother, Amalija.

Amalija Knavs was a strong woman who always carried herself with grace, warmth, and dignity. She was entirely devoted to her husband, daughters, grandson, and son-in-law. We will miss her beyond…

As we previously reported ... the former First Lady announced her mother It's not clear exactly how she died, but Trump told a crowd on New Year's Eve his mother-in-law had recently fallen "very ill."

Trump also called the night Amalija passed a very sad one for the family, while adding she "has just gone to a beautiful place in the sky. She was an incredible woman, and will be missed far beyond words!”

The leading Republican presidential candidate is clearly prioritizing his family's mourning -- he's off the campaign trail after dominating the Iowa Caucus, and also skipped the E. Jean Carroll in NYC to be at the funeral.

One other takeaway from Thursday's service ... Barron's really grown up in recent years and is the spitting image of his father, when he was young. Check out the pics, especially the one where he's extending a hand to support Dad.

Amalijaand Viktor emigrated to the U.S. years ago and became citizens in 2018. Melania and her 78-year-old mother reportedly shared a strong bond, and she'd lived part-time in the White House and recently at Mar-a-Lago.