I am left handed and thought about this for a long time before buying my first guitar. I decided to play standard and do not regret it at all. For many reasons.
1. In general it is easier to find standard guitars. Yeah the stores have left handed ones and you can order them but there are usually many more options to choose from if you play standard. Also if you go to find older guitars or buy them somewhere like a pawn shop they rarely are left handed. This also comes into play when you play a guitar that isn't yours. If you are sitting at a friends house or anywhere else there is a guitar it will most likely by standard. So if you learn to play left-handed you won't be able to play unless you planned on it and brought your guitar.
2. When playing standard the left hand is actually doing the harder part by fretting. I found it much easier to learn new songs because I was used to doing everything with my left hand.
3. If she hasn't learned before it doesn't matter which way you learns it will all be new. So if you had no idea which side you where supposed to have the neck on you would really care.
4. This is just personal opinion but I really think that left-handed guitars look wrong. They just don't look right for some reason. But maybe you like the look of it.
In the end it is all up to you and what feels natural. I think there are many advantages to learning to play standard but all that matters is which way you prefer.