Britney Spears Shares Throwback Pic of Jamie Lynn, Crops Out Mom Lynne

Britney Spears' recent post deserves another look ... 'cause it seemed like an innocent throwback with her sis, but it might've been a coded dig at her mom.

The 42-year-old singer-songwriter took to Instagram Saturday afternoon to share a sweet pic from back in the day with her sister Jamie Lynn Spears ... showing BS in a black turtleneck with JLS pulling off 2000s chic in her brown cap and bright orange T.

Brit captioned the pic, "Throwback!!! I can't stop laughing" followed by some laughing emojis. She even went as far as tagging her sister in the caption ... so it seems the two may even still be on speaking terms!

However, another family member was also in the photo, but didn't make the cut on Spears' IG grid ... 'cause Lynne Spears is off to the left in the actual pic!

Here's the full photo from way back in 2002 ... and there's Lynne in the bright red top, pearly-white smile on her face.

So why didn't she make the cut on Instagram ... there are any number of innocuous reasons for the exclusion like Britney only wanted to show her and Jamie's faces -- both of which are highlighted by rather funny expressions. Or, perhaps, the full pic wouldn't fit on Insta, so Britney was forced to cut Lynne out.

But, with all the turmoil in Brit's family from the past -- and the fact that Spears didn't even mention cutting her mom out in the caption -- it's always possible the two had another falling out despite their attempts at reconciliation.

We broke the story ... Britney and Lynne started working through their issues weeks before Mama Spears attended her daughter's 42nd birthday celebration at the beginning of December.

Everything seemed to be heading down the right path ... with Lynne expressing hope her daughter would come to Lousiana for Christmas to keep the good times rolling.

Since then though, we haven't heard a peep ... which suggests the wheels may have fallen off their relationship though we certainly don't know anything for sure.

On a brighter note ... Jamie Lynn seems to be back in Britney's good graces! We knew a reconciliation between the two was also taking place back in December though the actress wouldn't tell us anything when we caught up with her at LAX.

So, it seems we'll just have to wait and see if Lynne has anything to say about getting the axe from Brit's pic.