Sometimes corns will regurge if they are fed during the shed cycle. But there are lots of possible reasons for them to regurge. Some of the others are being feed too large of a prey item, being fed again too soon, being handled or otherwise stressed while they are still digesting, or having temps that aren't warm enough to digest properly.
It is highly recommended when you get a new snake that you give it a week or so to settle in to its new home before you attempt to feed it. This is related to the fact that stress can cause a regurge, and it can also cause them to just refuse to eat.
The fact that you fed your snake while it was still settling in, and/or the fact that you gave it 2 meals too close together (I never feed more often than every 5 days) may have led to the regurge, or it may be related to the shed cycle, or it may be that the snake wasn't healthy when you got it. We'll probably never know.
Now that she has regurged, you need to follow the regurge protocol to get her healthy again. Regurges can be very dangerous to snakes, and it is very important that she does not regurge again.
- The first step is to make sure you have a proper enclosure with the appropriate temps and plenty of hiding places, since improper temps or stress can lead to the regurge.
- Wait at least 10 days before you try to feed her again to give her digestive system a chance to return to normal. During this time leave her alone as much as possible. Don't handle her unless it is necessary for tank maintenance. Don't hover over her enclosure looking at her, etc. I know it is hard when you have a new pet, but it is important.
- When you do feed her again, offer her a smaller than usual meal. Since she regurged after a meal of only one pinkie (although one could argue it was 2 pinkies just spread out a little more than usual...better to go smaller and be safe), I suggest you offer only a pinkie head. If you cut off the head while it is still frozen, it won't be messy. If you are feeding live, buy one a day in advance, and put it in your freezer. It is considered humane to freeze them when they are that little.
- Consider ordering NutriBac, which is a probiotic and can help their gut flora return to normal. I consider it optional if a snake has had only one regurge, but a necessity if a snake has 2 regurges.
- Assuming the pinkie head stays down, continue feeding small feedings that are at least 5 days apart, and gradually increase the size of the feedings until she is back up to her proper sized meal.
- If at any time during the regurge protocol something comes up to make you need to change the feeding schedule, such as going out of town for the weekend when she's due to be fed on Saturday, choose to delay and slow things down instead of feeding early. Similarly, if she goes into shed, wait until after she has shed to feed her (you should probably do this as a general rule anyway). Missing a meal or 2 sounds horrible to humans, but it really isn't a big deal to a healthy snake, and having another regurge would be far worse for her.
Good luck, and don't hesitate to ask more questions!