I am certain that the two dreams are related. I can't be certain of the rest but I'll give you my opinion.
I believe you are right that the first part is about your plans for a new way of life and new baby. It is generally a good sign to have a baby who is healthy. They can often represent new possibilities opening up to you, creativity and hope. It could also just be a reflection of your desire to conceive, but I feel there is more to it than that based on what you said about other plans.
You seem to be very busy in the first dream with the new baby, which seems to lead to the second dream of loosing your daughter. Maybe you are feeling a little overwhelmed with the notions of a new baby and new way of life, and it is causing some worry about neglecting your daughter. The new baby and new life would take a lot of your attention away from her. You might feel to absorbed in minor details (tending to the routine needs of the baby) and forgetting what is most important right now. Your daughter could also represent other aspects of yourself that you feel are being overlooked or undernourished. I don't think that your daughter is in danger of being lost, but it wouldn't hurt to pay her some special attention anyways, since you said you do have fortuitous dreams.
That's just my take on it and certainly not gospel! I don't know how many kids you already have but just one is enough to stress a person. Combine that with a big change like you have planned and you have the potential to be overwhelmed. Take it easy on yourself. I hope this helped a little and good luck:)