I think just because you are concerned then a macaw might not be best!
Macaws are very big on bluff, and if they know you are scared of them biting, they will take advantage of that!
Fargo has never been aggressive to me (yet), he has bitten me once when his leg got caught and i had to free him, got about 6 punctures in my hand!
He will let ANYONE pat him, aslong as they arent scared, if you have confidence, straight away he will just close his eyes and absolutely love scritches, just complete strangers, however my mum is scared of him biting, and so he will bluff and pretend to attack her!
Fargo has never bothered biting me, because i dont find the beak scary at all, he knows it wouldnt get a reaction, and he is very well trained!
After working with big horses that rear, and buck, his tiny beak is nothing in comparison!
He actually did pinch for the first time the other day! But that was because i was putting alot of pressure on him with training on the floor, he thought it was a game, he had enough, ran over to me, pinched, and then ran away

I actually thought it was hilarious, so did he, but he knows that he isnt allowed to do that, and he has been an angel ever since
But that pinch hurt alot more than the 6 bites i got in my hand hahaha
U2Gal, thats not entirely true! Both my horses would just sit with me all day if they could, they love me, i even fell asleep with one of them lying down together outside! And they are grown up!
We even had a cow who we had since she was a calf, she is about 9 years old now, and she thinks she is a dog, and loves everyone
and i have my cat who i rescued when she was 5 days old, she is 7 now, she is the most cuddliest cat i have ever met, all she wants to do is sit on you and get cuddles!
Just because they grow up doesnt mean they dont stay sweet, friendly and loving to everyone!
I know Fargo is still classed as a baby, but he is ALOT more affectionate and cuddly now, than he was when he was when he was younger!
Of course i expect him to be different when he is older, just have to wait and see!
That was a very big post! Sorry!
Good luck with your decision, i think you need to interact with your baby and see how you feel, if you are scared of her beak and biting, then it might not be the best choice, but if you do think you could overcome it, then you will have a best friend for life!
and yes, Wendy is completely right with the mess they make! Fargo turns wood into splinters all over the floor, plastic toys chewed up and chucked everywhere, leaves and branches everywhere

But i actually love cleaning, so thats no troubles! haha