New CB Radios

[Bully13]

So I got two handheld CB radios and had 6' whips mounted on the bumpers on both of my Hummers. They work great when you are 40 feet away, but when we are at real close range, I can't make out what my wife is saying from the other vehicle. Strangly enough she can hear me fine. She tried just using the little antenna it came with while we were at a light and I could hear that clear until we took off again and went out of range. So her whip seems to be the problem I am guessing. Can anyone help with this?

I can't seem to get a good signal when I am close.