“I wouldn’t say that stressed is the right words but D2 clearly watched D1’s process and decided to follow a different path”
This was our experience also. The main difference I saw was that D2 had solid safeties lined up. D2 seemed to want to reduce the stress.
D1 had schools that we knew she would get into, schools she was willing to attend, and schools that we knew she would be able to afford, but they weren’t all the same school (she did end up with a merit scholarship that made her first choice affordable, but this was not a guarantee up front). D2 applied to several schools that were both very good matches and safeties. The only issue was deciding between several good choices.