Some women feel extremely ill throughout their pregnancies, constantly vomiting is in itself debilitating.
Indeed it is, GrannyGravy13. Some women end up in hospital because of hyperemesis, and if your DIL has it, I'd say she is ill, OP. Can you not spare a bit of sympathy for her as well as for your friend? I'm sure they'd both appreciate any support that's going.
Some women are hospitalised because of hyperemesis, one being the Duchess of Cambridge.
I felt ill throughout my first pregnancy, sick, as if I had flu and so tired I slept about 18 hours a day.
Sympathy, kindness and understanding should not be a limited resource and I hope you can find enough for both your friend and your DIL.
Both need your love and support.