I had IVF. My girls shared nothing in the womb and all the docs said they were fraternal. I, having read up on the subject, knew they were talking nonsense. As the PP says there is still at least a 25% chance they are monozygotic and only a DNA test done after birth can tell for sure. She should prepare herself to get LOTS more misinformation, LOL. In our case, the girls looked completely different from the get-go including different hair and skin color so we knew they are dizygotic.
With my IVF we transferred 3 embryos too, but it's possible for only one to take and then split. One of my docs told me about a case where two embryos resulted in quads - both split after transfer!
I second the info on Dr. Luke's book, the Elisabeth Noble book, and Mothering Multiples.
Dr. Luke's website is www.drbarbaraluke.com
. A great gift if you want to get pricey is to actually buy her Dr. Luke's consulting service. It cost me about $250.00 I think two years ago and it was worth much more. She is a gem, that Dr. Luke. She even called me in the hospital during one of my many stays.
You might also get her a subscription to Mothering magazine. It's a great magazine and resource as well.