Hi Realnappiesmum,
I'm glad you've got some answers... I know it's a difficult road ahead for you, but your little girls has the best of starts ? a Mum and Dad who already love her unconditionally.
I have two friends who have recently had children with Downs Syndrome, one little boy is just three, the other is the same age as my youngest, give or take. (2 and a bit.) Both are delightful, engaging children, who play beautifully, are very affectionate (far more than my DD2 which makes me a bit 
especially when they're getting a cuddle and my DD2 is wrestling me going "Stop it Mummy! Get OFF!"...) and a joy to have to visit.
At church there is a wonderful girl, she's about 18, with Downs Syndrome who volunteers with the children's ministry. She often helps out in the pre-school room, where she is "chief cuddler" and usually has three or four pre-schoolers jostling for space next to her for story-time. She's wonderful, and a really important part of our church community. She's always there, greeting everyone with a smile and a hug, she knows everyone, everyone knows her. She's a huge blessing to everyone she comes into contact with. My children think she's the absolute bomb.
(My youngest, incidentally, is convinced she's an angel. She may be right, actually.)
I'm sure for these children's parents, their lives have become rather different to what they imagined. And not always easy. But honestly, these children are wonderful, and very, very special.
Really really pray that other health issues get sorted, and that your little girl is born healthy and happy.
She's very lucky to have you as a mum, and I'm sure she'll give you so much more than you can ever imagine in return ? as all children do.
Much love,
db
xx