To provide a clear answer, I need a bit more context about what you’re asking. “Brooke Allison” could refer to multiple people (a musician from early 2000s pop groups, or other public figures with similar names) and the phrase “what happened” could relate to a range of events or timelines. Could you specify which Brooke Allison you mean and what timeframe or event you’re interested in (e.g., a musical career, a news event, or something else)? If you’d like, I can outline likely candidates and common questions people ask about them:

• Brooke Allison Adams, a pop singer formerly in BG5 and later associated with YLA, with notes about her early-2000s releases and later group activities.
• Other individuals named Brooke Allison who appear in news or biographical sources.

Once you confirm which person and aspect you’re after, I’ll provide a concise summary of what happened with that person, including key events and dates.