Hi. I'm no expert but I do have 3 female and 2 male mollies and have had one of my mollies give birth 2 times and going by the pic you posted it does not appear to be pregnant. Having said that,you know the appearance of your fish on a daily basis. If it seems that her belly has gotten bigger recently then she most likely is pregnant. As far as giving birth it's very hard to put a time to it because mollies can actually sort of pick when they are ready. If she is not feeling safe she can wait to decide to birth the fry. But a sign that she is close and a good time to separate her from the rest of the tank is when she develops a bulge below her gills and her underside will become sorta square like. By square i mean her bulge or rounded belly will look more squared . from my experiences i would strongly recommend a net breeder as opposed to the plastic floating breeders. For 1 the slits in most floating birthing boxes are to big and the fry end up in the tank