Well, congrats on your DIL's pregnancy for your 5th grandchild.
I think, you son's wife should see a doctor. Not sure that advice from us would be any good, unless we got a doctor among us.
Malaria tablets can be quite hard on people. I didn't have to take them in ages, going to KTP and Addo for the past trips, but
I remember having taken the tablets one evening without food and I felt sick to the bone afterwards. Others get that even if
they eat. Not sure if your DIL took malaria tablets before and if so, how she responded to them. But even if she coped well,
you never know how her body might react now. That's why I said, she should rather talk to her doc / gynaecologist.