If you're happy to feed to sleep and lean towards co sleeping, baby could realistically be into the second year before sleeping independantly. Or longer than that.
If you're striving for baby sleeping independantly but want to do it gently (as in without any crying) you're going to need to embrace the tools of independant sleep - which would be the dummy at this age. Then a comforter toy/blanket towards 12 months old. At a younger age a swaddle is very conducive to independant sleep, but unless you were swaddling under 3 months this is not something you could start now.
Feeding to sleep is not conducive to independant sleep. The key is to help baby go to sleep where they stay asleep. That's why feeding to sleep and cosleeping work together, baby just stays asleep where they go to sleep. If baby's place to sleep is to be independent of you, sleep needs to start from a position of independence. That's why the dummy is a vital tool, it slows for independant comfort sucking.
Use that same premise for daytime sleep - that baby needs to go to sleep where they will stay asleep.
But with daytime sleep you have the added difficulty of there being less pressure on baby to sleep - the body needs to sleep but the need is not as great as at night when natural body rhythms pressure the body to go to sleep.
So you have to counter-act that reduced pressure to sleep, to over come it. It basically means you have to work harder for daytime naps, compared to night sleep.
I usually add in movement to help baby get to slerp in the daytime. Given you want baby to go to sleep where they stay asleep, that means naps in something that moves and going from awake to asleep in there. Pushchair, car seat or my favoured method - the bouncy chair.
Until about 6 months, when naps extend and spread out, I'd keep naos naps in something that allow a for movement, add in a dummy (to replicate feeding to sleep), ensure baby is well fed and has restricted awake time do not over tired. Then just be relentless about it.
My recommendations for gentle route towards independant sleep at this age would be:
In the night
Develop an in-cot way to resettle baby without feeding. Mine would be dummy and sidecar cot cuddles. If baby stores awake, give 5-10 mins to trying to resettle this way first, without picking baby up.
If resettling doesn't work then feed, but always try a resettle first. Feeding to sleep is inevitable in the first 3 months and is part of attachment parenting cosleeping. But by 4 months i wouod be sitting up in bed for a 'proper' feed, like in the daytime.
Pick up, feed both sides. It's inevitable baby will feed to sleep because the aim is to be awake as little as possible at night. But upon finishing the feed, kuft baby to your shoulder and wind a little. The shifting of position delays going into a deep sleep then put baby down in the cot.
Baby is not meant to be in a deep sleep at this point and might fuss. Dummy is key - it allows for the semi-conscious mind to continue comfort sucking. Place your hand on baby's chest to recreate the weight of being held by you. Just stay still, calm and wait. Keep the dummy comfort sucking going and stay physically close, head-to-head so baby can hear/feel you breathing.
At bedtime
Use a similar method to above. Feed in a "we are not going to sleep here" position, cradle hold for example. Lift to shoulder as starting to sleep at the breast. Wind cuddle/sway to calm baby if squirming from movement. Once calm, put in cot/crib.
Expect some squirming when putting down. Dummy, firm hand on chest. Lie down next to baby (on your bed). Head close so baby can hear and feel your breath as well as feel your hand. Without dummy this probably wont work. Dummy is pretty essential in my view.
If baby doesn't settle, try some gentle patting, stroke cheek, tap dummy. If the unsettledness becomes full-on waking up, lift baby, put back to breast and start again.
Daytime naps
Firstly and most importantly, limit awake time. The time between 2 sleeps shouldn't be more than 90 minutes. This is all day long, so your day will consist of blocks of time with 60-90m awake them 30-45m asleep - repeated over and over again from 7am to 7pm (ish).
These are when lying down breastfeeds and leaving baby there to sleep is useful. Dont try to move baby once asleep. As mentioned earlier, extra help is usually needed for daytime naps.
If you don't want to cosleep for the nap, bouncy chair would be my method of choice until 6 months old. With the activity arch removed, so it's just the chair.
Make sure baby isn't hungry and is winded. Into bouncer awake (awake!
). Position bouncer in front of the sofa at your feet. Have a cuppa and the tv remote control to hand. Draw curtains and turn volume down on tv if you think it will help.
Dummy in. Feet on the metal z-frame of bouncer and start bouncing with your feet. Gentle but rhythmic. You don't need to watch baby, that may well create too much stimulation for baby.
Just watch the tv, keep the bouncing going, reinsert dummy as needed, drink your
and be utterly relentless about it. Assuming you've not had a massive awake time (which would make baby over tired and need extra help to sleep) just trust you know best and... Keep. On. Going. Just keep going until asleep.
Keep awake time to 60-90m between naps. Expect short naps of 30-45 mins.