What's Going To Happen To My Betta Fish?

ok so please help. so i have that tiny little betta tank for two and it has the divider and the male made a little bubblenest but its tiny the female i know is a red cambodian but not sure of the male its purplish redish and so the female is pretty fat and has the white spot by the annual fin i think (i just got bettas but i know millions of stuff about them i have been reaserching a lot) and i just noticed the dot and when i take out the divider she just hides. so i put it back in and i know if i let them breed in the little thing the female's gonna die :( i have a 15 gal tank but my dad likes tiger barbs not bettas so i dont no what to do its my dream to breed bettas and i fell in love with them sooo much. before i thought the were like a big version of guppies but there not they'er amazing and i have a lot of felling for them please help i am tearing up and if you dont belive me i am a little girl who is a fish MANIAC!! ;( HELP please!!