I agree with what has been said so far... Take her in to make sure the infection doesn't need stronger treatment than just the Neosporin. If not, here is what I have done in the past...
Be sure you're using gold (white or yellow) posts until you resolve the infection and to determine if she can wear anything else. Remove the earrings at night. This way the ear can heal itself without the earring being tugged and pulled against a pillow, blanket, etc. After removing the earrings in the evening, clean the hole with peroxide then apply some Neosporin to the front and back of the lobe and massage it in. Allow the earrings to either soak overnight in peroxide or clean them well and put them away (use a Q-Tip or clean toothbrush to really clean the earring). In the morning, clean the hole again, rinse the earring with peroxide(unless it was soaking overnight), dry it, dip the post in Neosporin, and reinsert it. Be sure to always handle the earrings with clean hands and tell her to not play with or tug at them if at all possible. Also, if she has long hair, you may pull it back for a few days until you get things under control so it's not getting caught on the earrings. Even though it doesn't hurt, it can still tug on them unnecessarily.
Once the infection has been cleared up for a while, if you want to, you can try posts other than gold and see if it starts to return. If so, you know that's the problem. Whatever kind you buy, make sure they are hypoallergenic. Best of luck!