First things first: Congrats on the news! Having a new baby in the house is always exciting news!
I have no advice on the breastfeeding, I only BF'ed each of mine for 6mos-1year and then was done with that!
What if it's another girl? Having 3 daughters would be just wicked cool! Don't get me wrong boys totally rock, IMO...I am a Mom/Auntie to 6 boys and 1 girl, so I am totally partial to boys... but the thought of 3 girls would be just so very sweet!!
Having my 3rd was THE best decision my husband and I ever made-------> right after having our 1st and then our 2nd (besides choosing each other of course) Ha! We had 2 boys and then a lil' girl and she completes our lil' family! Girls are just so amazing! We really are so much more superior in so many ways :)
All 3 of my kids are each 2 years apart and I think it's the perfect spacing. They are close enough to share the same interests and to go to school together (which I think is important, it's nice to have someone to show you the ropes and most importantly to have your back, especially in HS) and *generally* speaking being this close in age, I think they have a better chance of actually getting along and liking each other b/c they grow up playing together and are essentially each other's very first 'best friends'.
~But I might be biased, I only have 1 older sister and we are 2 years and 1 day apart and are very best friends, always have been, always will be! We had a few minor disagreements along the way, in HS b/c I always wanted to borrow her clothes...usually without asking... but other than that, we talk almost every day, we are less than 3 months away from being 38 & 36! Yikes! and have never gone a whole day being mad at each other...which I think is pretty darn cool!
The only thing I would be (slightly) worried about is if the 5 1/2 year old is going to feel like the odd man out? If you have a boy though I bet that won't be an issue at all?! So as cool as 3 daughter's would be, I ( once again, if I were you) I would be having my fingers crossed for a lil' boy! But as long as he/she is healthy that really is all that matters...it will all work out just as it is supposed to in the end, that is totally my motto anyway!
Just my .02 cents. Didn't mean to let my worrier side come out and spill all over your good news! Sorry sister! <3