A source tells ET that the 37-year-old Flip or Flop star "hates" to see her second marriage come to an end, "but she also knows she must be true to herself and she just feels they aren't a good match."
The source adds that though "Ant has tried to do what he can to hold the relationship together," Christina "just wants to move forward."
"Christina is going to take this time to heal and spend time with her children and focus on her show," the source says of the mother of three. "She and Ant plan to co-parent their son and remain friends."
Christina is mom to 1-year-old Hudson with Ant as well as 10-year-old daughter Taylor and 5-year-old son Brayden with her ex-husband and HGTV co-star, Tarek El Moussa.
"She is a wonderful mother that went through a very painful, very public divorce and never took the alone time to find herself, to rebuild her strength... before she was planning a wedding and a baby shower," the source says of Christina's split from Tarek in 2018.
The source adds that Christina and Ant's romance "was like watching a fairy tale in fast motion" and friends "advised her to take it slow" following her divorce from Tarek.
"When she got engaged, they expressed their concern," the source says. "It all happened so fast. Christina never had a moment to take a breath."