Saying Katie is successful depends how you define success. I personally question her credentials. Katie is a brand manager but yet there was no evidence of that on the task when they had to design a trainer. Also, on the art selling task, she got the strategy wrong and undermined Adam who actually had the right strategy and went on to sell. On the French task, she demonstrated that she was more subjective than objective and supported the other upper class twit when he purchased industrial grade cheese to sell to the French.
I've said it before and I'll say it again. People like Katie are successful career-wise because they go to the right school, meet the right people, use their contacts, manage upwards, surround themselves with people who can do the work whereupon they step in, take credit without giving credit to where it belongs and they reap the rewards.
Her performance on the Apprentice bears this out.
Whether she is a good mother etc does not interest me. What I do know, she is a very unpleasant character who is condenscending, duplicitous, arrogant , untrustworthy and has questionable morals, especially as she is always wishing other dead!