9 week old suddenly not sleeping at night

[TMC83]

My 9 week old has suddenly stopped sleeping for long stints through the night. She was sleeping 4/5 hr stretches and now is awake every 2 hours through the night. I’m not aware of a growth spurt at this age. I’m just wondering if this is normal and whether it’ll pass and she goes back to her usual stretch? I’m really sleep deprived at the moment and worried if it continues.

4-5 hours is amazing for that age isn't it?

Mine were up every 3 hours for milk up until about 8 months.

Yes I really thought it would happen that she’d start sleeping longer. A few nights she was asleep 6 hours! My sisters baby is 12 weeks and from about 6 weeks she’s slept through the night and is now even sleeping for longer like 7/8 hrs. I feel so envious and just don’t know what to do to get my little one to sleep for longer 😩