ECE is not the same as CE, and neither major should be confused with CS.
If your daughter wants to do CE, will she be ok with the additional electrical engineering classes she’ll need to take at CMU for the ECE major? Engineering is hard, and a lot harder if you don’t like what you’re doing.
CMU does have a grind culture where many students pride themselves on how intense their course load is and how little sleep they’re getting. Not everyone there is like that of course, but overall it’s a very intense, and not necessarily collaborative environment.