Like, she had every right to be there in my opinion. Her brother was there and her practically daughter Sherry was there.
Her brother needed to get back on his feet. I honestly thought that Jill was going to do it, but Piers was a good character, but he NEVER mentions, 'hey besides that your men died, your SISTER is worried about you' like why wouldnt you mention that? surely she would have known or have just been worried about her brother?
Sherry was allowed to leave gov. grounds since Wesker 'died' 3 years prior to RE6. I understand that Simmons was a jerk and probably wouldnt let Claire see Sherry but Hunnigan was helping Leon keep tabs on Sherry and i almost garentee that Leon (or Hunnigan) relayed that info to Claire. And wouldnt Claire be very upset and worried when Sherry goes missing for 6 months?!
On another note, Claire hasnt seen sherry in person for a LONG time, and im glad that Sherry got to see leon.....but why not Claire? Claire is like a mom to Sherry....I think she should have been partnered up with Leon so when Jake, Sherry & Leon all met up in China, Claire would have been there too. it would have been a cute reunion i think.