I totally agree that you should get a guidebook. I prefer the Unoffocial Guide to Walt Disney World. My kids' first trip was when they were 2,2 and 4. I read the guidbook cover to cover and planned my day around what I knew they would like. We could all give you advice, but ultimately you know your child's tolerance level. Everyone said that Snow White was way too scarey for young kids, but my kids had been watching the movie for months before the trip and they absolutely loved it. So, you can only go by what you know your daughter would like. On our first trip we did Dumbo, Cinderella's carousel, Peter Pan, It's a Small World, Pooh about 40 times, Snow White, Buzz Light year, Tomorroland Transit Authority (surpisingly this is really a nice relaxing and fun ride), Toontown, my 4 year old did Goofy's Barnstormer ( you probably shouldn't do this pregnant), Haunted Mansion, my 4 year old was tall enough and did both Splash and Thunder Mountain (not good for pregant women though), The Disney railroad, Pirates (can be scarey, but the kids liked it), Jungle cruise and Aladdin. THe parades were the biggest hit that first time. It is a good way to see all the characters without waiting in lines. We spent 3 out of 5 days at MK because this was so much fun for them. We did MGM and AK, but MK was the best.
Good luck.