How about colorful espei rasboras & cardinal tetras, a big bunch of each. And loaches (of course), kids often like kuhlis or sidthimunki have a lot of personality & may help with any snail control that you might need. Or skip the sids & try red cherry shrimp, kids like those too & they can help with algae control.
				
			 
	 
	 
 
		 
 
		 
 
		 Occasionally female bettas can be aggressive though, so with a bunch you'd be quite lucky if everyone got along, but in that size tank it might not be an issue.  They come in so many pretty colors, too.  A large school of black neons are also pretty, and a little different than the common neons or cardinals.  I hope you'll share pics of it when you are done.
  Occasionally female bettas can be aggressive though, so with a bunch you'd be quite lucky if everyone got along, but in that size tank it might not be an issue.  They come in so many pretty colors, too.  A large school of black neons are also pretty, and a little different than the common neons or cardinals.  I hope you'll share pics of it when you are done.   
 
		 ( good luck!!!!
( good luck!!!!