As he spent a month with her family, I would have thought that would make it less likely he was being scammed, unless they are not aware of the requests for money

If she has been ill and visited hospital then she will have hospital bills, get him to ask her to scan some in and email them to him, maybe he could email the hospital and confirm the details ?

Being pregnant, having anaemia, leukaemia and then a scan and having her phone stolen have to be warning signals he might have been scammed

Why no passport? Maybe she doesn't have a birth cert, or possibly she is already in a relationship with someone or married? Does sound something is not right that after 2 months she hasn't got one. What's her reason? Has she applied??