Lynne Spears is obviously keeping a close eye on Britney's social media, as she left a comment on her Friday IG post about the "fairytale" ceremony. Lynne said, "You look radiant and so happy!"

TMZ broke the story ... when Brit and Sam decided to tie the knot last week at their Thousand Oaks, CA home, Britney's mother, father and sister, Jamie Lynn, were all left off the guest list.

Still, mama Spears gushed in her comment, "Your wedding is the 'Dream' wedding! And having it at your home makes it so sentimental and special!” Lynne added. "I am soooo happy for you! I love you!"

The only family member Britney invited was her brother Bryan, and although we saw him all dressed up with his date hours before the wedding ... he ended up no-showing.

As we've reported, Britney's been on the outs with her parents and sister since her battle to end the conservatorship heated up last year. The singer has threatened to sue all of them -- and her attorney, Mathew Rosengart, is currently trying to get Jamie Spears to sit for a deposition.

With that backdrop, it seems unlikely Britney would be thrilled about her mother's reaction to her wedding. If you're a glass half full person, though, it could be seen as an olive branch.