I just did something crazy…

My baby sister, idk if yall remember but she’s irresponsible and was hooked on drugs, she is about to have a baby and has been contemplating adoption. I just told my family that I’d adopt the baby. It’s a girl so we already have everything. She would be 3 months younger than my Marianna. It would be hard for a little bit but I am confident that we would all adjust and love her as our own. What would make it a little easier is that we are moving out of state and would be able to raise her without issue. I did tell my family that we hope she decides to become a mother and work on herself to be a better person but if she decides to not keep the baby we would be a safe place for her to go. I think I have the patience to care for a child with disabilities due to my sisters history, there are no signs now of that. But just something that has run across my mind. Am I crazy?? Or would you do the same?