Hi Ted,
It depends on how the V sign is made or given. If someone flicks you a V sign with their palm facing outwards towards you, it is generally accepted, worldwide, as meaning a sign of peace that indicates solidarity or approval. It actually originates (as we know it) from the peace movement and the 'flower power' (hippie) era of the 1960's: "Love, Peace and Freedom" - and of course was stronly associated with Vietnam War protestors.
However, if the V sign is given with the palm facing backwards towards the person giving it, particularly with an upwards thrust or motion, it is a gesture of contempt or implies a rude insult ie "Get stuffed!".
Winston Churchill the British Prime Minister used the V sign ( palm facing backwards and forward!)as a symbol of victory and defiance during the second world war. And it was later popularised by the Beatles pop group as a sign of love and peace in the late 60's early 70's; hence their songs: "All you need is love" and "All we are saying, is give peace a chance".
You won't see many people over the age of 25 years flashing or flicking the peace V sing in the UK, but it is widely used by young people in Japan. It is also used by many of the younger Chinese girls in their Chnlove profiles!
As a sign of peace or solidarity it is almost always accompanied with a smile - and, as that it what the young lady gave you, I think you may safely accept that is what her V sign was saying to you!
Hope this is of some help? By the way, the next time your wife is upset or angry with you, just flick her the V sign, making sure the palm is facing outwards of course!!!
V = Peace brother!
Johnboy