If she's as nice as you put it, I assume she's just misinformed. She wouldn't intentionally mistreat a pet.
I would point to her tank and ask her how many gallons it is, as if you don't know. When she answers, either right or wrong, ask her if she knows the minimum tank size for a betta. Correct her with the correct 2.5 gallons, and discuss about it.
There are two more options.
You could also drop by the $1/gal sale and buy her a tank, and give it to her as a gift, tell her it's for her Betta, so she doesn't stock it with more fish. You could do something like, sit her down, and explain the proper care of a betta with physical examples, and when you're done, and she fully understands, give her the tank gift.
You could also direct her here, to this forum, but some people can get a bit out of hand when it comes to care, so that one's a bit risky.
I would point to her tank and ask her how many gallons it is, as if you don't know. When she answers, either right or wrong, ask her if she knows the minimum tank size for a betta. Correct her with the correct 2.5 gallons, and discuss about it.
There are two more options.
You could also drop by the $1/gal sale and buy her a tank, and give it to her as a gift, tell her it's for her Betta, so she doesn't stock it with more fish. You could do something like, sit her down, and explain the proper care of a betta with physical examples, and when you're done, and she fully understands, give her the tank gift.
You could also direct her here, to this forum, but some people can get a bit out of hand when it comes to care, so that one's a bit risky.
