Sentence:  She's her own woman, major, first, last and all time. If she can't be the <WSD>bell cow</WSD> she's not going to trail along. That's all there is to it. 
Meaning of the word marked with <WSD> tags:  A leader; an influencer<ref>W. Davis Folsom, "Understanding American Business Jargon: A Dictionary", Westport, Connecticut: Greenwood Press, 2nd edition, 2005, p. 27.[https://archive.org/details/understandingame00wdav]</ref>.