AGREE, ship her asap and be done. We do not keep any fence jumpers or "high - headed" cattle as they will teach all the rest to be that way. I always like to give them a chance as they sometimes have just had a traumatic experience. But, the older I get the less tolerant I am. If that neighbor is getting some of his in to ship to market, then just let him take her on with his and have him put her in your name. Give him something for hauling and don't even worry about your neighbor having to deal with her. If he is going to cut out some of his but not ship them, then I agree, let the neighbor get her on the trailer and not get off til she is in the stockyards. Give him something fair for taking care of her and transporting her and be done.
If the others have some brown or reddish in them then they could very well have some other blood in them besides angus. Or they could be a little vitamin deficient, as that will cause hair coats to be reddish sometimes. Make sure they are getting minerals along with a salt block, or use a mineral mix that has salt in it. They will grow better if they have the needed minerals.