Paracetamol is normally what we be used. They come in 500mg tablets and you can take 2 to start. Don't take more than 6 a day though. Also, if she is also experiencing nausea, you could try Paracetamol 500mg / Metoclopramide 5mg tablets. Both of those would be available over the counter.

Edit: You could also ask them about Paracodol, which is 500 mg of Paracetamol and 8 mg of codine. Normally, in Europe and Canada it is available by just asking the pharmacist for it, however, I'm not sure how they handle that in SXM.