Feeling confused?

We have the most perfect 17 month old daughter, who was our rainbow baby, and we are now trying to have our 2nd rainbow baby. I had a miscarriage in November. While I am so excited to have another baby, and give our daughter a sibling there is this small part of me that feels sad. Sad that it won’t just be me us and our daughter. I fear she will feel sad. Anyone else feel this way? Any advice?