There's just one leetle problem with that theory: she's not rocking an engagement ring — yet! Maybe she really is waiting to make the announcement on her birthday, which by the way is only two days away!
Despite the absence of a pretty little bauble on her left ring finger, auntie Pippa still looked lovely in her sleeveless, aquamarine-colored Logue London dress and Jemima Vine snakeskin slippers.
She was also carrying two bags, including an Aruna Seth tote slung over her left shoulder, and shielded her eyes from the sun with Givenchy shades.
And in case you're wondering about the diamond ring on Pippa's right hand, we're going to stop you right there — it's an old ring she's worn countless times in the past.
We eagerly await your announcement on Friday, Miz Middleton! Or should we say the future Mrs. Jackson? Ha!
[Image via XposurePhotos.com.]