enders game - Why was the Bugger Queens of Second Invasion so close (in Solar System)?

According to Ender Canon, Mazer Rakham won a Second Formics Invasion by figuring out the pattern and finding and destroying the Bugger Queen's ship.

But as we find out later:

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  Formics' Queens can communicate with the "worker" buggers via philotic connections

  
  
  


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  This communication is instantaneous across any distance.

  
  

So, given this:

why was the invasion-commanding bugger Queen situated right there in Solar System where she could be destroyed in the first place?

I'd prefer an in-universe answer or at least an authoritative (e.g. from OSC) one, not a speculation.

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UPDATE: Please note that "The Formics didn't realize that the queen was in any danger and thus needed to be protected" seems to be 100% wrong according to "Ender's Game":

Ender : "They make that ship move just like any other ship";

Mazer : "They know it's their weak point."