I personally like to split the transfusion and cross match otherwise you will be waiting around for a long time.
Sometimes it can take hours to find a good match. You also don't want to be tired before they do the IV as this will make it harder on you and your little one. You want yourself and your daughter as relaxed as your can be before they do her IV. The first few times are very very difficult, the babies veins are hard to find and babies get very upset. Our first few times were very hard, my husband and I both cried the first time our son got his IV. We have come a long way since then. But your patience and attitude will determine how soon she relaxes afterward, and the way she reacts to her IVs in the future. I know how you feel at this time, I remember being obsessed with this feeling of fear and a sense of loss for months when we found out about our son's thalassemia.
I am confused why your doctor thinks that the IV may not stay in. We have never heard of this. Our son has been transfused since the age of 3 months the IV has always stayed in. I have never heard of this, there are possibly 20 transfused patients at the hospital patient where our son is transfused and I have never heard of them having problems as enfants. Maybe this is something I don't know about, perhaps this does occur but I don't know about it.
I am sure there are people who have ports and advocate them, but in my personal experience the one little girl who has a port is the least well adjusted to her treatment. Again these are all my personal opinions and they reflect my understanding and knowledge.
My thoughts and prayers will be with you as you get through this initial hurdle.
Sharmin