Hi, I'd like to help you with your question.
When kids go from high school to college, the adjustment can take a while. Suddenly, they are no longer at home under Mom and Dad's watchful eye. They are independent with few restrictions and suddenly an adult. Some kids take time to realize that the discipline has to come from within and no longer through their parents or teachers.
Your daughter sounds like a mature person who may just need some guidance. To talk with her, try these steps:
Allow her to know that you have expectations that her grades are good throughout college, particularly if you are funding college in any way. Keep your expectations realistic. A's and B's are good grades but expecting all A's may cause too much pressure and she may rebel or just not be able to maintain the grades and fail.
Approach talking about her grades without judgment. Emphasize that you want to keep the communication open between you and that you are there to help, not dominate.
Keep in mind that in the first semester of college students grades are usually lower than in high school until they adjust. So getting worried now may be premature.
Don't ask outright how her grades are or if there are any problems with her affecting her grades. Try connecting to her and get her talking about things in general. You could start with talking about home and what has been going on, mention what is for dinner, ask her if she'd like to go out with you one day and do something fun, etc. Reconnecting to her on her level will help get her talking, so when you bring up college, she may be more willing to keep talking.
Try not to quiz her. Weave comments about school into your regular conversation. Treat it as part of her life but not the total focus. The less intensity on her about school, the less likely she will try to avoid the topic.
I hope this has helped you,