She can take paracetamol. In case this isn't a miscarriage I would avoid ibuprofen. Unfortunately at this early stage there's nothing can be done to prevent miscarriage if its happening. She can wait it out and make a GP appointment but it if she develops severe pain or bleeds very heavily/become very pale/faints you need to take her to the emergency department.
'Heavy' bleeding is soaking through a pad or tampon in an hour or less. I would suggest avoiding tampons anyway in case it is a miscarriage as could increase infection risk. If she is in pain, pale or just seems really unwell as has been said then don't hesitate, get help. Keep her warm and a hot water bottle might help with the cramping too.
Sorry I should have said, sorry to read you're facing this. It's just something that happens in some pregnancies, neither of you will have done anything wrong to cause it and chances are you will have a successful pregnancy in the future.