Fry struggling to swim!

Do you have a picture of her?

The betta fry you find in stores usually end up with issues. I breed... And sometimes I see fry who have a "heavy bottom". Most of them grow out of it. Another issue you may find with the pet store fry is bloat - SBD, swim bladder disorder.

Floating, and tilting to one side is usually a sign of SBD. Try to avoid any freeze dried foods... Try crushing the pellets, and maybe offering frozen foods such as brine, bloodworms, Mysis, etc.

As for now, try to fast her for a day. Another step is adding a couple teaspoons of epsoms salt (1-2 per gallon should do the trick), as it will help her poop!! Clears them out fast I tell you! Your water temperature is at the perfect spot which does help digestion.

You can keep her on Epsoms salt for up to 10-14 days. Do daily water changes and replace the water you take out (unless tank is cycled, then you may want to do it a couple times a week). Make sure to finish at least a few days after she is better to ensure she does not relapse... Trust me, it sucks to have to do it all over again!

Definitely. They tend to eat a lot more than they should! I keep an eye on their tummy size whej I feed mine. I have one (adult) male who eats about 8 pellets... He's a thick bodied HMPK lol. But a halfmoon I have eats only 3.

Try feeding her three times a day, smaller meals. This will help her grow, but keeps her from bloating I have a young female and she has doubled in size since I had her - and I feed my fish very well!