How do we do this gently? I'm a WAHM so I've been with her nearly every day of her life. She's very independent but she still needs me. She still nurses. She sleeps in her bed, in our room, for the first half of the night but is always back in bed with us by morning. She's 20 months now, will be about 2.5 when baby comes.
Re: transition from only child to big sibling.
We have Dr. Sears' books about bringing a new baby home. They're awesome!
We also got DS his own baby to hold and love (or not, depending on how he is feeling). He loves his baby and brings him everywhere. We got this one:
https://www.amazon.com/gp/aw/d/B004KS2T84?pc_redir=1409148054&robot_redir=1
We've done some talking about what will happen when baby brother is born. He knows that mommy and daddy will have to go to the doctor for a whole day for baby to come out, and he knows that his uncle and aunt will come to play with him while we're away. When he asks if he can see baby or whatever, we say that baby is still too small to come out. He has to grow grow grow before he can be born. DS comes with us to every appt and ultrasound and is involved in every part of prep for baby brother.
Baby brother will bring a special present for DS home from the hospital. And we will have some fun activities and snacks and stuff planned for DS and his aunt/uncle while we're away. And DS went to build-a-bear and made himself and his baby brother teddy bears, so he has a bear to give to baby brother too.
So that's what we've done to prep our boy. He is in his own bed in his own room now (bedshared until age 2), so cosleeping isn't a concern for us. He also weaned a few months ago. Are these things (nursing and cosleeping) that you would like to change before #2 arrives, or are you interested in tandem nursing and cosleeping with two? It's entirely up to you!
https://www.amazon.com/gp/aw/d/0912500972?pc_redir=1409140281&robot_redir=1
Also, bedsharing or cosleeping can definitely be done safely with 2. It just requires some care to be taken. Sidecarring a crib for baby to have a safe place to go while you nurse DD is a great idea, and remember to not have the kids sleep next to each other. Baby should be on the outside always, and DD can be between you and DH or on the outside next to DH.
Next, have daddy do some of the bedtime routine and do the rest together. E.g. Daddy can take bath and teeth and you both read books together with DD and both are there until she snuggles to sleep. Switch up what daddy does on his own vs. what you both are present for.
Then let daddy do all of the bedtime routine on his own. Maybe you need to run an errand while they do this, so that you're not there to take over. Try every other or every third night, and on all the nights when you are there helping, make sure daddy is heavily involved in bedtime...maybe a hassle, but until she's used to and happy about daddy taking the lead, he needs to be involved in EVERY bedtime, even if he isn't doing it alone.
This worked for us for DS. Nowadays, DS begs for daddy when I'm snuggling with him and begs for me when DH is. Lol He will go to sleep with either of us, but it usually takes a bit longer with DH and he does typically wake sooner during the night calling for me. It's SO worth it, though, because if DS won't go to bed with DH when LO2 arrives, DH will have to be on baby duty all late evening. :P