Somebody buy Tiffany Trump a diary!

President Donald Trump’s only daughter with his second wife, Marla Maples, wished her older half-sister, Ivanka Trump, a happy birthday on Friday.

But the Instagram message to her “best friend” was three days late.

It’s not known whether Tiffany Trump sent a private message to her sibling on her actual special day, but she blamed her delayed salutation via social media on “law school life.” The 25-year-old is currently a student at Georgetown Law.

Ivanka Trump, a senior adviser in her father’s administration, turned 37 on Tuesday.

Last Christmas, the siblings were teased on Twitter for this bizarre Mar-a-Lago holiday video: