Do NOT step in her life and start making choices for her concerning her friends. Basically our job as parents is to prepare our kids to live in the real world and prepare them to make the decisions in their lives, by using their best judgment. While they're still living with us, it's our opportunity to allow them to mess up because at their ages, the lessons are cheap, not like when they're out in the real world. What I mean is, if you allow her to get hurt by these friends she's choosing, then when she's out on her own, she's less likely to get caught up with someone with low morals and who can get her in trouble, and the trouble won't be with mom and dad, it will be the law. You could say something like "Boy, that's too bad that your friend ruined the beginning of her adult life by allowing herself to get pregnant. What do you think she's going to do now?" See what she says and you could say something like "Wow, I just can't imagine what my life would be like if I hadn't been able to enjoy my early twenties and get my degree. What are you going to do to make sure that you don't get in that kind of trouble?" That way, you're not lecturing her, but rather, leaving the decisions in her hands, while letting her know that it's something that ruins lives. Like, with the stealing, instead of getting mad at her friend, force your daughter to take responsibility for her by saying, "well, it looks like your friend stole $25 from us, plus $10 for the items she took. How would you like to pay me back? Do you want to pay me back now, or should I just take it out of your allowance?" This forces her to make better choices. It teaches her that if she's going to hang out with friends who do things like that, she's just as responsible for their behavior as they are. This will make her think twice about inviting her over to your house again too. There are so many ways that we as parents can get through to our kids, and the ways don't involve yelling and lecturing. Just try to use a creative way and make it fun and rewarding to both of you. You get your money back, and probably get rid of any chances of that girl ever coming back to your house, and your daughter learns that the people she chooses to be her friends affect her life by involving her in their schemes. The next time, if it ever comes up, that she asks if her friend can stay the night, make sure you say something like "well, since you've paid off the things she stole from last time, sure she can, but I'll be keeping track of things that may come up missing and if you can't afford to pay for them, than I'll be finding things in your room to take that will cover the cost."
I just read your "what happened". That really sucks. Children have to learn consequences. Thank goodess it happened before she turned 18. If I were you, I wouldn't discipline her about it, because she'll get disciplined by the law, but I would maybe say "wow, that really sucks because now you'll have to face the court. What are you going to do? Do you have any ideas yet on how you'll pay for it all?" That way, she makes the decisions and suffers her own consequences.