Whatever other people tell your SIL about labour, don't let her take it as gospel! Every woman will experience labour differently - and she'll experience it differently with each child. Until she gets there she won't know how it will go (I always had bad period pains and expected it to hurt - I shocked everyone by not finding labour particularly painful and by being so silent the MWs asked me to tell them when I was contracting as they didn't know!) Fear releases adrenalin which is exactly what you don't need when you're in labour - anything she can do to stay relaxed will help (taking her own pillow, pictures, essential oils to mask "hospital smell" - or staying at home altogether )
Birth as potrayed on most TV shows (especially Casualty and ER) tends to be overly dramatised - a good birth is much more calm and peaceful and doesn't tend to oinvolve emergency life or death decisions. Being aware of what can happen allows you to make a more informed decision more quickly - but expecting it can frighten you silly.
For new borns, I was told 3 things by my MWs:
- you can't spoil a newborn baby by picking them up
- they grow up inspite of you, not because of you
- this, too, will pass
(oh, and the good old moving goal posts of "the first few two days are the hardest", "the first weeks the hardest", "the first month's the hardest"...)
Don't feel you have to be polite to visitors - tell them if its not convenient for them to come around and kick them out when you've had enough. It might help to establish "visiting hour(s)" for a while if things are getting out of hand.
As well as not feeling suprised if she doesn't feel a bond straight away, don't feel suprised if there's a very strong one - I had problems with my in-laws as I found it very hard to deal with other people taking DD away from me (especially when she started crying and they wouldn't give her back). Looking back I should have said more sooner rather than sitting getting stressed, but at the time I felt I "had" to let them hold her.
If she finds it hard to ask for specific help, have a notice board somewhere with a list of jobs on and just ask volunteers to do whatever they feel up to.
Pin a checklist of "obvious" reasons why the baby might cry on the back of the door (hungry, wet, dirty, cold, hot, wind, cuddle) - by the 3rd night with no sleep you can start to forget a really scary number of things
A good sling can be a sanity saver if the baby wants to be held all the time - I used a stretchy wrap (this one, but there are plenty of others), which has MUCH better weight distribution for both adult and baby than slings like the Baby Bjorn.
Sorry that's such a random selection of thoughts . Hope she has a good experience, however it pans out, and doesn't find life with a newborn too traumatic