Well, I was hoping for Lynda Carter.
I thought maybe they were going to be "realistic" about the fact that the Amazons are ageless, reaching full maturity and then stopping. So it would make sense to cast someone who was no older than the actress playing Wonder Woman. But Connie Nielsen is 49 or 50 so they are ignoring that in favor of audience expectation that a mother will look very clearly much older than her daughter.
But, based on what everyone is saying, it looks like the actress they cast will do a great job.