She looks to be not pregnant, and not overweight at all. c: However, if she's ever been in contact with a male platy, there's a good chance she'll be pregnant soon. Livebearers can hold onto sperm for months.
Impossible too tell. Imho it looks very healthy and doesn't need a diet. Assume it is pregnant if it had had contact to any male before.
Haha! I'm a woman for starters! So our fish dropped her fry a few days ago! I managed to catch and separate 5 of them! So she was indeed carrying babies! My kids (3,6,8) are so excited! Such a great learning experiencegratz your a dad!