#2 Moving into a proper part-time role

A year would be the minimum that Ronda Rousey would require if she does have a child. Even so, if she does return, it's definitely going to be in a more part-time role rather than the current role she has now.
She has the leverage to do it, because she was one of the biggest box office attractions in MMA history, and the undisputed queen of the box office in female combat sports.
Look who just shut down all of Tony Khan's critics! More HERE.
She could either have the Brock Lesnar-type of part-time role, where he rarely appears at all, or she could do it like John Cena, where he appears continuously for a period of time and then takes a hiatus of a few months.
Hopefully, it's the latter.
#1 Another shot at Hollywood

This is an unlikely option but still a big possibility. Although Rousey wasn't particularly successful in Hollywood, she's still a big mainstream name, and being with WWE and training in the Performance Center would have definitely helped her improve her acting skills quite a bit.
If that is the case, then she has a higher shot at success and may be looking for a less physical way of earning a high income in the future.