I'm surprised that she thought the right thing to do would be to post this instead of helping this other person.
She even said she received an email from the correct Sarah in 2008 so she knew exactly how to contact her, but instead she tried to log into her Photobucket account.
The dot doesn't matter to gmail. It matters to other services. Way back when I first learned about this feature, I registered for some website using first.last@gmail.com.
Unfortunately, when I later had to verify my account through email (as opposed to clicking a verification link) the website did not recognize firstlast@gmail.com (my sender address) as the account owner.