11 week old sleeping through the night?

Hi! Not bragging, just genuinely confused about what happened last night.

My LO is 11 weeks old and until this week slept swaddled in a bassinet next to me, usually waking only once to feed. Then she started trying to roll, so we stopped swaddling.

Night 1: absolute chaos. Two hours to get her down, then 1–1.5 hour stretches all night.
Night 2: better, but still more wake-ups than usual.

Then last night she brought back the witching hour with an hour of nonstop crying, so naturally I prepared for war.

She fell asleep on me around 9:30. At 10:30 I transferred her, she woke up, and I left her awake in the bassinet while I got ready for bed, fully expecting to have to rock her for ages.

I came back… SHE HAD PUT HERSELF TO SLEEP?!

And then she slept until 7:30 AM. No feeds. No startle wake-ups. Nothing. Just a little complaining when she rotated herself sideways in the bassinet.

So… what just happened? Is it okay to let an 11-week-old sleep that long without feeding, or should I be waking her?