Its really more of a statement turned question and to me at least indicates surprise/incredibility. I've seen a few other threads on this problem but generally verb first in German translates better as "do/does ... <verb> ... ?" while as object first can be translated word for word " ... <verb> ... ?"
I tried to type Kennt Sie euch on purpose, and it was correct. I think in this case it should at least give me some warning because sie=she and Sie=them or you formal. I know that the suffix of the verb would be different but written like that, it would be considered a grammar mistake rather than a typo, if that makes a sense for you. what do you think?
euch = personal pronoun = you (accusative plural, informal. Therefore the discussion about "you all," "you guys," although the use of these forms are by all means not required to mean more than one when you say "you" in English.) Example: How are you, children? / Wie gehts euch, Kinder?
eure = possessive pronoun, accusative case = your (feminine singular, and plural masc., fem., neuter.) Example: I like your duck. / Ich mag eure Ente. (Hunde, Katzen, Hemde.)