Haha! Very true!but my general rule of thumb is that if she's a livebearer, she's pregnant!
The biggest tip for getting fry to survive is hiding places, and well-fed adults. The more plants, the more places you'll have for fry to escape, as well as forage. Looks like you're well set up!
If you've got a cycled tank that's hospitable to a fish that size, you might as well transfer over sooner rather than later. Stressing out a pregnant mama fish can interrupt the process and you can lose a batch of babies if you cause too much stress right around when she's ready to drop.