I have an juvenile endler with almost all of its colors in a tank with 1 month old females. I'm not sure about the male endler's age but will my females get pregnant and die?
Most female live bearers sexually mature at around 5-6 months old, with genders of both male and female becoming distinguishable at around 6 weeks old. Males mature sexually at an earlier age. It is recommended to separate males from females at 3 months just to be on the safe side, as in certain water conditions, such as those with elevated temperatures and ample food supply they are know to mature more quickly.
Also, certain species mature at faster rates than others, but generally all common live bearers tend to stay within the confines of the guidelines I have just laid out. (Aside from before mentioned circumstances of varying conditions)
If you are certain they are females than they should not get pregnant, however I would not leave them in the tank with your Endler for more than a month or two if you want to be certain that no reproduction takes place. Also, it is unlikely they will die
A true endler can be quite productive at only 3 or 4 months old. A guppy endler/cross, which is far more likely these days, will not likely be able to produce fry until about 5 months old.
There is no general rule KrystaK. Every species has its own rules.