Tell me your sleep training experiences with a 4 month old please

[thingymaboob]

DD 4 months old.
Currently waking every 45 mins, sometimes 1.5 hours. The regression, I know.
Naps in day are all in sling. Use wake windows as a guide etc.
EBF. She's in a cotbed in our room, still swaddled in a swaddle bag. We play pink noise through the tommee Tippee dream maker. Good bedtime routine, bath, song, cuddle. She is rocked and shushed to sleep. When she wakes I sometimes just cuddle & rock but feed every 3-4 hours.
I always wait for her to cry, I don't respond to fussing but all wake ups involve a cry.
I have successfully used controlled crying before but my other DD was 10 months.
For those of you that have sleep trained a 4 month old, what method did you use and was it successful?
I have tried Co-sleeping. It DOES NOT WORK. Everyone's sleep is worse. I don't know who these children are who sleep soundly next the their parents.

4 months is too young to sleep train, it should be 6 months at the earliest. I know it’s a struggle!

You are going to get a lot of people telling you not to sleep train a 4 month old. I disagree because I think there are some very gentle and effective methods at this age.
I would first look at overall routine and feeds though. What is happening currently?

Wakes at 7
1st Nap in sling 1 hr 45 later
2nd nap 1 hr 45 mins from end of first nap
3rd nap 2 hrs from end of 2nd nap
4th nap 2 hrs from end of 3rd nap
Naps vary in length.
Bedtime between 8-9:30 currently.
Feeds happen immediately after naps and before bed and first thing in morning. Roughly following Eat, activity, sleep.

It’s because she doesn’t know how to fall asleep herself. Get rid of the sling. Will she nap in the pram on a long walk?

raisingchildren.net.au/babies/sleep/settling-routines/helping-babies-sleep-settle-3-6-months

Yes she is contact napping and being rocked to sleep so it would be better to set up some more sustainable sleep associations. Pick up put down works well at this age with much less crying than other methods but ONLY if you put the baby down as soon as they are calm and drowsy, not asleep.
Routine sounds fine. Are you breast or bottle feeding ?

If you can hold out until 6 months I'd put her in her own room and sleep train then, we did it at 6mo and it worked a treat, but I probably wouldn't do it before 6mo. I recommend a gentler version of Ferber combined with pick up put down - put baby down awake but sleepy, do 2, 4, 6, 8, 10 (no more than 10) minute intervals, go in and pick up and soothe and put back down again saying the same phrase e.g. it's sleepy time. Repeat at every wake up. DD cottoned on very quick and we thankfully didn't have the multiple nights of no sleep that some have. Good luck!