Did you get any treatment for your hyperemesis gravidarum? Just be aware that there are drugs and treatments available, in case you want to have more children in the future. Biofeedback and acupuncture help; conventional medicine tends not to be as effective, but there is one medication that can help a lot.
You said one thing that really hit the nail on the head for me: "We being clueless on what children need to do...." Have you been using any baby books, or have you been pursuing more of an instinctual approach to parenting?
I've found, actually, that very little "instinct" has helped us with our daughter. I think the reason is that, while it could be great, we live in a society surrounded by unnatural things, so I think it's hard for us to really discern what our instinct is telling us and what our unnatural environment requires of us.
There are so many pediatricians, psychologists, teachers, and other experts that are the top of the line in child care issues, while there are so many experts in other realms of life. Our knowledge of so many things has updated and become so much more sophisticated and helpful to us in so many areas of life, and child care is, I think, one of the most important areas to keep our knowledge as up-to-date and full and well-rounded as possible. If we know the latest on how to lose weight or get our finances into shape or how to buy a car, or gardening techniques or household gadgets or electronics, we can just as easily learn the inner workings of a child's mind, how to interact, what best treats colic (no instinct will tell you to lubricate a thermometer and insert it into that baby's rectum!), and of course, milestones.
So. As soon as you can, go to your nearest library and get some books - not just on milestone sorts of things, but baby stuff, all things related to toddlerhood.
Here are some books that I've found very helpful:
The Sears Baby Book by Dr. Sears
The Sears Discipline Book by Dr. Sears
The Happiest Toddler on the Block by Dr. Harvey Karp
Easy to Love, Difficult to Discipline by Dr. Becky Bailey
The Sears Nighttime Parenting Book by Dr. Sears
I'm not saying your baby has discipline issues. These are just great books and they talk a lot about what goes on in those little heads of theirs. So they're great for just understanding how babies "work."
You will love them.
L.
PS Hi, C., I just came back and read what I wrote, because I had written it in a hurry and had a feeling it might have come out wrong. I'm not saying that you're not doing enough as a parent. I'm responding more to people who tend to pat a parent on the knee, at least figuratively speaking, and say "it'll all sort itself out, just relax and enjoy being a parent" when there are resources out there that are available to us. I think Lena's suggestion, for example, was great! (I just always think in terms of books ;) I think that what I was trying to say was, do whatever it takes to give your daughter the best this life can offer.
Also, there is information about hyperemesis at helpher.org where they talk about studies involving the effects on babies of moms with hg. Sorry, I forgot about this earlier.
PPS about her speech delay, get the book BabyTalk, which describes a very simple program for babies, toddlers and young children that, studies have found, helps them to develop their speech/language at accelerated rates, and many children who started out behind even end up in the gifted range. It's also great for emotional growth and discipline - you'll see. Get that book, it's marvelous.