Hi Wanda -- I have no idea what Joanna's last name was, or who her parents were.However, I'm of the school that believes Howell Brewer was Ambrose's father, simply because the name Howell comes down through the family, and the name Lanier doesn't.To my knowledge, there is no real proof of Ambrose's parentage -- if you've got documentation, please share!!!
Same for the wives of Ambrose -- I'm not sure that there's proof on any of them, except possible Mary Oma Richardson.She is mentioned in her father's will as married to a Brewer, and although both Richardson and Brewer researchers have assumed it's Ambrose, it doesn't actually say that.
Keep in touch, especially if you find documentation on any of this Brewer clan!!!