She often starts slowly, but she is dumping a lot of shots into the net, or wildly long. She is starting to warm up a bit though. Bencic is the Olympic Gold medallist and, like Emma, hasn't lost a set in this tournament so far.
On balance, there are going to be nerves, but this is impressive stuff so far from the young lady in the full context of the occasion. When a rookie goes a break down in the opening set, there's often not much coming back from that - I think this girl is made of sterner stuff.