Sorry for your loss with the first petco betta Luimeril. Sometimes bettas are just too sick from bad conditions in those cups to make through a transition into a new home. Poor things. I worried about my petco baby for weeks until I could see some growth & some of the redness on his gills went away. He's doing great now, getting bigger & some color, & very, very feisty.
Cammy sounds like she's in good hands now & will be great. Post an updated pic after she settles in if you can. I love seeing the before & after pics of bettas. It's just neat to see how they color up after they finally settle into a new home.