The singer is estranged from her parents and siblings.
"Gonna go lay under the tree to remind my family that I am a gift," the post read.
"You were the first baby girl of the three of us! We all saw you as a precious gift!" Lynne commented, before referring to her late sister, Sandra Covington, and Sandra's daughter, Laura Lynne.
"Aunt Sandra sooo wanted a little girl! Then came Laura Lynne!" Lynne wrote. "My sister and I so enjoyed having you two and sometimes in the same crib!"
Lynne concluded, "You have always and will always be my gift!"
While Britney deleted the post that her mom commented on, she reposted the same quote hours later.
"Ever since Britney and Sam [started] talking about getting married and planning their wedding, inviting them was never a question," the source said.
While there was speculation that Britney's brother, Bryan Spears, may score an invite to the wedding, he did not attend. His girlfriend, Amber Conklin, said on social media that she and Bryan did not attend because the nuptials conflicted with their daughter's fifth grade graduation. Britney, however, denied that Bryan was invited at all.
"You were never invited to my wedding... You hurt me and you know it," Britney wrote in part in a fiery Instagram post. "I know you're my blood and yes blood runs deep but no family of mine would do what you guys did to me. GO F**K YOURSELF Bryan -- F**k you."
The Spears clan may not have attended Britney's the wedding, but the mother of the bride did comment on her daughter's post about the nuptials on Instagram.
"You look radiant and so happy," Lynne wrote. "Your wedding is the 'dream' wedding! And having it at your home makes it so sentimental and so special! I am soooo happy for you! I love you!"