OK! That tells me lots. Thanks!
I can see where you went wrong yesterday. The very first nap of the day happened 2h20 minutes after she woke up. At 4 months old, most LOs can handle about 1h45 of awake time. So she was awake 30 minutes more than she could handle, which explains a 20 min waking.
Then the 2nd nap she was only awake 1h15. I realize she only slept 20 minutes, but for some reason they all have a limit where you can't put them down TOO early or they have an UT nap (which is what she did, at 40 min).
Her next sleep happened 2h05 later. Too late, especially since she has 2 crap naps in her.
See what I'm saying?
So, let's start to day with a VERY strict 1h45 A time and see how she does. That means even if you lay in her bed from 6-6:50, her A time starts at 6. If it takes 15 minutes for her to fall asleep typically, then you need to have her IN BED at 1h30 (which means wind down starts at 1h20). I have a feeling, tho, with better timing she'll probably fall asleep in 5-10 minutes, so I'd start wind down at 1h30 and have her in bed by 1h40.
See how that goes!