Take the bell off the collar. It is probably the ringing that is upsetting Cole. Also, try to give Cole a space of his own that the kitten can't get to him in - especially if she won't leave him alone. Think about it from his POV, there is was enjoying a nice quiet life in his house, and then all of a sudden there is a mad lunatic tearaway disturbing his peace that he can't get away from. It's like having a rude hormonal 15 year old human teanager you don't know moving into your house and giving you grief 24/7.
When my latest cat, Lily, was a youngster she was a class A Mental Hoolikitten. She traumatised every cat in the house. Eventually we got into the routine of putting her to bed in the study with a litter box about 10pm every night so that the others could have quiet time. It seemed to ease the tension considerably, especially with my timid cat.
As for Collars, 4 of mine wear one, my 5th cat just can't deal with one, they stress her out far too much and frighten her.
Good luck - maybe give Ruby time out in your daughters room at bedtime every night.
RC