Gentle ideas will take a long time. As long as you set your expectations to allow for this being a very slow and gradual change then you can make changes to your baby's sleep without lots of crying and distress.
The idea of any gentle method is to make tiny changes that gradually over-time lead to the end-point you want to reach.
So I assume that in the long term the factors you want to change are:
- having to walk up and down to get her to sleep
- Having to rock her to get her to sleep
- breastfeeding to sleep
and then in the long term I assume you are aiming for
- being able to fall asleep in her cot
- being able to fall asleep without your help
- being able to fall asleep without your presence.
To set some realistic expectations, slow gradual gentle changes to get to this end-point might take 2 or 3 years. But it's doable.
My suggested start point would be the walking up and down. So you keep the BF to sleep and you keep the rocking to sleep. But gradually over several weeks you start walking slower while BF and rocking. You do it gradually but still continue BF as you were and rocking as you were. And you carry on walking, just slow down the walking until the point comes that the walking can stop. Set realistic expectations, this might be a few months.
Once you don't need to walk, just rock and BF, then work on slowing the rocking down. Again gradually and slowly over several weeks until the rock is so small and slow that the movement is barely there.
Next work of getting her to accept BF to sleep with you seated. Then with you lying next to her. All of this might take a long, long time and all you have done so far is stop the aspects of falling asleep that you want to stop. The next stage is to introduce the aspects of falling asleep that you want to develop.
But please don't worry. It is entirely doable to get to the end-point you want to without distress or crying. It might just take a long time.
Another alternate is to just wait it out. Carry on what you are doing and in or 3 years the problem may well solve itself without you doing anything. It depends whether what is happening now is reasonable and can work in your family longer term.
I hope this helps.