It’s helpful to know what the symptoms are and to seek advice if necessary. The NHS Covid symptom checker provides guidance and can also provide a note for work: https://111.nhs.uk/covid-19/
Government guidance is clear that if anyone has symptoms, they should self-isolate along with everyone in the household.
It is important to keep up to date with the latest government guidance.
It may help to carefully consider what arrangements would be reasonable to take account of the most up to date government guidance and to manage a parent or child becoming unwell. For example, it would be reasonable to agree that a child should not move from a household where no one has symptoms into a house where someone has symptoms and should be self-isolating with other members of the household. Equally, if someone develops symptoms, everyone in that house at the time should self-isolate together in line with government guidance.
If you do need to alter the arrangements, you can try to find other safe ways to keep in contact. Your safety and the safety of your children is paramount. Make sure that you are happy with the form of communication suggested and have considered how this could impact on your safety.