Hi there!
Congrats on your new addition. We also just brought a 16 year old Congo to our home, about a month ago. She has changed a lot as the weeks have gone by...we get to know her, at her pace. I know it is hard to let them do this, but it is really important for trust building. The biting is something that I was very fearful of too..but that fear instilled an EXCELLENT observation ability on my part of her body language...obviously in order to avoid being bit. I have learned that the biting is just an inevitable part of being a grey owner...so being very observant and learning her moods will be your best ali...when she is pinning and crouching, it is best to respect her boundries and leave her be. She does not have hands to push you away with, so she is using what is available to her.
Please please read the top ten list of deadly foods, in the "feeding" area..http://www.greyforums.net/forums/showthread.php?137487-Top-10-Common-Foods-that-Can-Poison-Your-Bird. It is an invaluable list..I know it is redundant to you maybe, but there could be things on the list you aren't aware of yet that could save her life. Not to be dramatic..but it includes things like apple seeds...things that are very basic and have a high potential to find its way in her beak if you arent aware of them. I know many of them were surprising to me.
As you get to know her, it is really, really neat bonding with them. I take Kihei on field trips around the house, for enrichment...and let her explore the faucets, and the counter tops, my son's toys, etc. She is like a toddler...EVERYTHING goes straight to her mouth. I think this exploration also helps the bonding process too, and keeps her happy.
Good luck, looking forward to getting to know you.
Logan