It sounds to me as if this previous queen was not socialized well and was kept away from human interaction while breeding. This is really sad as it's difficult to socialize an older kitty. You've had her for a year and there's not been much improvement. This is because an owner has to work with the kitten. If she's left to do what she's always done, she will not become a more socialized cat. Bonding comes from interaction with the cat, making sure the cat gets interactive play time with toys.
Now you have a new baby and babies come with cries and new smells and mommy has to spend more time with the baby than the cat. Bengals are vocal cats anyway. You've decided to allow her outdoors, which only solves the problem when she is outdoors. Unhappy cats usually seek out new homes, so are you prepared to lose her? Your first priority is your new baby, but you also do not want your kitty to feel left out and abandoned. She is part of your family, too.
I'm going to suggest you visit
http://www.spiritessences.com and see if any of the formulas there might help your kitty. Bengals, for the most part, are very social cats and want to be with people. Your little girl needs reassurance. This is truly sad because she should be an integral part of your family and want to be a part of everything in your lives.
Allowing her outside to roam around is not going to help her shyness as there are a lot of noises out there that may startle her and she will run in the opposite direction. Bring her back inside where she will be safe and try spending more time with her. Make sure she has a tall cat tree, lots of wand toys, and that she gets some gentle petting, and talked to in a soft voice. This is probably not going to stop her vocalizing as that's what bengals do.
I know you have your hands full, but I hope you're able to help this little girl.