T.D.
Ryan was formula/bottle fed from the beginning. I didn't transition to a sippy until he was about a year old, when I did, I gave him his bottle with whole milk for about a week, then just used the sippy with milk from then on. He had no problems transitioning. I have a friend whose son wouldn't take a bottle, went straight from breastfeeding to a sippy! He was taking formula in the sippy with no problems either. You might have to try a couple of different types of sippys until she finds one she likes.
I have been through every solution for leaky night diapers. I was changing a wet bed in the middle of the night A LOT. I have tried night diapers (waste of money) diper inserts (I was having to use 2 at a time) and finally discovered what works for us. I use one size bigger diaper with a bladder control pad in it. I feel strange buying a huge package of bladder control - maximum protection - supersize pads (LOL) but hey it works. The bigger diaper is just at night to compensate for the extra bulk from the pad.
I don't know what brand of diapers you use, but I've found that Pampers are more stretchy than Huggies which is helpful to cover everything and get them fastened tightly. We used Huggies in the beginning but have switched to Pampers because they seem to work better.
Good luck!! I know what it's like to be up in the middle of the night changing wet sheets and doing lots of laundry. Yuck!
~ t