I don't know if you want my opionion, alot say you HAVE to keep them in a 5 gal tank so my opionion is only that
ITS A FEMALE! 2 things give this away on why the 1 thing is very obvious and even someone saying you HAVE to have it in a 5gal tank should see this!
Its a female! 
Edit: and for the record so EVERYONE knows females flare as well as males so you can't use that as a sign they are male and female especially if they are babies!