Cancer isn't contagious. Hugging and kissing your sister cannot pass her illness to you or your baby, and your visit cannot affect her cancer either way. Being
pregnant doesn't change this.
Next Steps
If your sister currently has a cough, cold or fever alongside her diagnosis, it's still sensible to wash your hands and keep some distance this close to your due date. Otherwise there's nothing specific you need to do.
Health Tips
Please consult your obstetrician if any new symptoms come up, and continue your routine antenatal visits as usual.