Worried about my girlfriend

So I've been dating this girl for a couple of months, everything has been fantastic, the normal problems of any couple nothing to worry, we have a very stable relationship but one day talking about our sexual experiences she told me that the biggest cock she's ever taken was 11 inches, mine is just 5.9 inches, I've never worried about my size but now I feel a little insecure as she also told me that she could take it full. Should I feel bad? I think not, but it's twice as much as mine, and I've noticed she exaggerates her moans when we have sex, I don't want to ask about it because I know she would tell me mine is fine even if it's not true