Can you provide a little more info? Where is the leak coming from in relation to the engine (front of engine, middle, rear?)? Also what type of car is it (year, make, model, how many miles), and lastly was the car serviced recently?
As mentioned, it depends where the leak is coming from. If you use a quickie lube type of place to do your oil changes, it could be that they didn't tighten the drain plug completely and it is dripping. As well, most drain plugs have a silicon or steel washer on them that wears out over time, so it may just be that the washer or drain plug needs to be replaced. Also, if the filter is loose or has a defective gasket, same thing. Those are the most common problems if the leak just started, After that, if the leak is coming from the bottom of the car, it could be a crack in the oil pan or the oil pan gasket, but a very small chance of this unless she hit something.
If it were me, I would go to the local auto parts store and get a new drain plug for about $5. Just tell the clerk the year, make and model and they can look it up for you. Then search your local paper for a $14.99 (or so) oil change coupon and take it in (if it is leaking heavy, check the oil level before driving it, and using a different shop than the one you normally use would be good). When they change the oil, ask them to use the new drain plug, and make sure you get the old one back (to insure they did install the new one). Also, any decent oil change shop would do a basic inspection and tell you if there was a crack in the pan, etc. After the oil change is done, tell them about the leak and ask if they noticed anything unusual. If it is a quick change place, they have no reason to lie for the most part about a major repair because they can't do that type of work anyway. Give it a day or 2 and see if the leak persists. If it stops, it would indicate the filter or plug was the problem.
Lastly, if it an older car, the solution may be as simple as using an oil specifically made for High Mileage cars. Sometimes the seals in the engine become brittle over time, and an oil like Maxlife has special seal conditioners that can slow this problem over time.
If none of these stop the leak, a good local mechanic will need to get involved.
Hopefully some of this info will help, and I'll keep an eye on this for more info on the car.