Some full-time Realtors actually have full-time jobs. There are no set hours in real estate. Clients often ask real estate agents if work in real estate full time but they never ask agents if they have another full-time job.
There have been times over the years when I have taken in additional work. During the housing market crash and great recession, I had some part-time gigs with a couple of companies on the west coast.
Working with home buyers means having to be available all the time because houses just don’t stay on the market very long these days. Working on the listing side is a little more flexible and in this market, the sellers really are calling the shots. Real estate agents have to be available to answer questions about the house and keep an eye on showings and feedback.
As long as two jobs can be worked one at a time instead of at the same time it can work. Working full-time at two jobs while caring for children might be more of a stretch.