Actually I don't think "sumimasen, onegai shimasu kedo" is a valid phrase, or at least one I've never heard or used. Asking a favor is normally more like "chotto/sumimasenga, onegai ga arimasu;" please is just "onegai shimasu;" while requesting information would be "nani nani wo onegai itashimasu" or some variation thereof. Where did you get this one ?
OK--you'll have to deduce her intentions by whatever happened next, then. Context matters a lot in these things. If a person just said "Onegai shimasu" out of the blue it sounds like an emergency -- please help me or I'm in trouble or something.