Hi sweetheart. You're such a gem for seeking information for your friend! Last year we had a fresh cycle and I only had 3 or 4 embryos from memory, and we decided to grow them to day 5 in that cycle. In the end we had one embryo which made it to day 5, but instead of it being a blastie, it was a compacting morula. They weren't 100% happy with it as it was slightly lagging behind, but it was good enough to put inside. Unfortunately this cycle didn't result in a pg for us. We were later told the grade was a D I think, so it was a pretty poor grade to begin with. From my understanding, an embryo that is lagging behind has a lesser chance of a viable pg but not always. I really hope your friend's embie goes the distance, my FS always says, better for an ambie to be inside than outside.