If you put her on the spot by asking her direct questions and she seems uncomfortable, then it is probably the least effective way to get her to open up (very good at slamming the door shut actually). This will apply to her all ages, especially teenage years. Instead, relax and let her open up to you when she's ready. Listen for those opportunities, and then shut your mouth. If you are listening and observing, and not talking, she will tell you what's going on in one way or another.
Also, baby her, love her, cuddle her, spoil her, indulge her. Studies show that children become more independent when their needs are met, and if the need is denied they become more insecure and fixated on getting that need filled!
Also, I made the same mistake of thinking my son needed to be more independent before the baby, but it doesn't work that way. You need to fill her reserves with tons of love, attention, cuddling, focus and attention in order for her to get through the desert of mommy's attention that will be the first 6 months of baby's life. I also relied too much on others' help with my son BEFORE the baby was born and that was a mistake because he needed me then, when I was still available for him. If you're tired, get help everywhere else, except with spending time/attention on your daughter.
Let go of the little stuff and relax your standards. I, too, felt that all of the things I was enforcing were extremely important for a well-adjusted adult, but later realized that enforcing many ideas can actually be counterproductive. Let them live a little more than you were allowed to as a child -- that is probably what is holding you back from 'spoiling' her more. This is very difficult and counterintuitive to do, but it will pay off in the long run.
A good hint I've noticed is that when I've reached the end of my line or when the kids are going crazy, sometimes I need to do something for *MYSELF*. Ever notice how when you're really happy or having a good time the kids tend to be happier & well-behaved too? Bottom line: you relax, she relaxes.
Good luck and congrats on #2!