I have my Platy since 7 weeks and she was fine. All my concerns I had before resulted into having fry - she had 3 times babies over the past 7 weeks. She is finally skinny, so I think we are done with getting babies (I have 2 female platies in the tank - we should be done!). Now she rests on the bottom of the tank all day long. She only seems to get up, if she looks for food. What's wrong?