can't tell coz the pics are too small. But generally if the fish has grown fatter over a month, and she has been in a tank with a male molly sometime during the last 6 months, then she is pregnant.
they are usually pregnant for about 4 weeks when kept at 26C. Cooler temperatures will take a bit longer. Warmer water can speed the process up a bit.
26-28C is a good temp for them when pregos.