tb you were away for 6 months or more,
anything could have happened during this time,
isn't your daughter 14 years old, isn't it possible your wife left your daughter home to watch your youngest while your wife went out to the store or somewhere else? People having an affair make time to have an affair.

Look you're right, there may be no affair whatsoever, but she sure is acting poorly and irrationally towards you while you've literally been away working in a war zone, pretty cruel behavior on her part, regardless if there is an affair going on or not.