Did your DC's sleeping change around 8 months?

Since 4 months old DD slept 10 hours at night (8 - 6) and would take 2 or 3 1/2 hour cat naps throughout the day.

For the last week or 2 it's different. She still wakes at 6 am, but if you just leave her in there she will quietly play for about 20 minutes and then go back to sleep until 8am (so that's almost 12 hours.)

Then she NEEDS to go back down for a nap at 10 and sleeps about 1 - 1 1/2 hour(s) Chat Icon

Then by 2pm she's cranky again and will sleep another 1 1/2 - 2 hours (and has done 3 hours once or twice.)

By 4pm she's yawning, but I keep her up until bedtime at 7:30

IMO that's a pretty big change. She's teething, so I'd figure the opposite. Is this another phase? Is she maybe not feeling well? I hate to question sleep, but for her its so NOT normal.

ETA I really like these new sleep patterns. I never knew what it was like to have some free time.