I looked at the growth chart...and I feel stupid because I can't figure it out

However Bella Joi is 4.5 pounds and born 10/6/2006. Does anyone have a guesstimate on what you think her final weight will be. One vet says she still has between 3-5 pounds to go. Another says she is done growing. Her parents are around her weight; but one of her past sisters were 8 pounds full grown.

Doesn't matter to me what her weight is really; she is a precious baby no matter how chubby she is. I was just wondering if anyone had any ideas?