Yes they can, we have a local news personality that has a 13 year old daughter that tested positive. All members of the household are isolated, he is doing the news from his dining room in the morning. She is on the third floor in a bedroom with a bathroom in full quarantine. Fourteen days after exposure for family.
That is the only way to stop the spread on COVID-19 (Trump skipped his Biology classes in high school and college).
If we started out with isolation for people in contact with positive tests we wouldn’t have 200,000 dead from COVID-19.