HI there. People usually say that non-trads get a little bit of a break on their UG grades because they are usually talking about grades that are ten years old. We then can reason that we have grown up and those grades are not reflective of who we are right now. BUT, if you are taking your undergrad classes now, I would say the grades are just as important as the 20 year old's grades that is sitting next to you in class.
Also, a lot of us have worked while taking classes and balanced a family too. i cannot really offer any advice save for the old "must have balance". If it is your dream, you can make it work.
Good luck to you!