betta fish acting funny

Question
Ok so i just bought a new baby female Betta fish she was n a small tank with a divider with my grandmas grown male Betta fish she was acting fine the day i got her n put her n the tank n the second day she started acting funny so i put her n our big tank with our other fish she was fine and swimming around for a few hours and now all she will do is lay on the bottom of the tank not swimming around or anything just laying there. My dad keeps telling me we can get another but im upset im already attached to her :(

Answer
With her being a young Betta, it is very important that a heater is being used and set between 82 and 85 degrees. The temperature has to be steady and not fluctuate. If no heater is being used, then I suggest you get one. Once she is about 9 months you can lower the temperature to between 80 and 82 degrees. Also, moving her around a lot will stress her out. Place her in her heated tank and leave her there. She will need time to get used to the new tank. This usually takes 3 to 5 days. If after she has been in the heated tank that long and is still acting this way let me know.