My son is now 20 mo and has been exactly the same since birth. We recognize what it takes to keep him content and try everything in our power.... We never close doors behind us, take him into every room, carry him whenever he needs it, hold him a lot, avoid most things that cause him sep. anxiety type issues, etc His personality has affected our family and made us adjust some of what we do/don't do. We can't both be in church at the same time because he doesn't tolerate the nursery without us, then if he's with one of us he cries inconsolably for the other. Car rides are sometimes impossible. It's all been a lot of work for everyone, but he us so worth it.
I have done some reading and fond that most reputable experts say that how to respond to a child that shows separation issues is to flood them with security.... Make them feel and know that you are going to be there and provide what they need right now. Even though it seems obvious to us that you will be back from the bathroom, shower, taking the trash out etc to and insecure child they do not feel that it's a guarantee.... They feel insecure and possibly abandoned. It's hard, but they need constant reassurance of security, to the point that it seems rediculous. If they are left to cry or not comforted when they are feeling scared/insecure then they will be set back from any progress as it only tells them that they do have something to worry about! As much stress and work that it is, if you provide constant security and sense of trust, she will be allowed to continue to grow and trust and eventually know that you are there for her even when not in sight or holding her. On the other hand, the more she is not responded to, the more insecure she will be for now.... Does she sleep with/near you? Does she spend lots of good quality time together each evening playing, holding, cuddling, interacting? I know you mentioned needing to make dinner when she really wants to interact.... Maybe do several meals in advance on the weekend so there is less work day housework and more mommy/baby time? She really needs you a lot right now....
Is it possible that her separation comes from her not feeling comfortable with where she goes or who she's cared for when you are at work? Just a thought.... Since she can't tell you, you can only go on her behavior and cues.