My dd2 who is 6 came up to me in the kitchen, rested her head against my tummy (just had dinner so was rather swollen lol) and said:
you look like you have a baby in your tummy - I'd like that - I'd be a good big sister
and wandered off 
how weird that was. We haven't told anyone we are ttc doe to how long it took to conceive dd2 (around 18mths). on cycle 6 atm of ttc #3 after swithering about it for 3yrs. nice to know she won't freak if we're lucky enough to get pg 