You'll have to excuse me but I an working with the app and the pictures don't seem very clear.
Since she is a lighter skinned Molly you should be able to see a dark spot near anal fin. This is called a gravid spot. It can be sometimes difficult to tell if a Balloon Molly is pregnant because of the appearance of the fish. If she is with a male it is only a matter of time until she is pregnant.
Good luck and happy fish keeping!
Oh and of course
~* Welcome to AA*~