My girlfriend and I are raising my sister after my parents passed away. It‘s a whole different set of experience, because she started living with us when she wa

My girlfriend and I are raising my sister after my parents passed away. It‘s a whole different set of experience, because she started living with us when she was 15. That was 2 years ago. (I‘m 33, my girlfriend is 39) And you realize that it‘s difficult to deal with someone who grew up differently. I left our parents house when my sister was 5. My girlfriend grew up completely different. And then you have a teenager, who, besides the fact that having a teenager is a whole different story, also doesn‘t share your mindset at all, because you didn‘t raise her. Our time is running up. My gf is turning 40 next year, and we don‘t have kids on our own. After these years (I think my sister will move out in the next 24 months, as she turns 18 next year), we are not sure if we want to have kids at all. It‘s difficult.