So, there are probably a lot of people with kids in the house that are out of school, trying to actually make a living while the world melts away. I am a work-from-home veteran. Here are my tips:
1) If at all possible, establish a place in your house that is your office. Wake up, have breakfast, and then "commute" to your office, even if it means just walking up stairs to the guest room or kicking your spouse out of your bedroom.
2) Your kids / family are not allowed to bother you while you are at the office. If they need something, they should send you an email or text and ask you for help. If it makes sense to take some time out of your work day, "commute" home, fix the issue, and then "commute" back to work.
3) Interruptions to your work day without the proper notification should not be tolerated unless someone is bleeding. Try to foster an understanding that this is just like mommy / daddy being 15 miles away at the office, and only bother me when it would make sense to call my office and ask for help.
4) Get your stuff done, and then "commute" home at the end of the day. Once you are no longer in your office, treat your home like you have treated it before. Answer any emails you would have, etc, but have the mindset that you are now home, and no longer on the job.
tl;dr - it is better to set up a barrier between home life and work life, even if you never leave the house. Blnding those two during the work day and after the work day is likely to lead to more strife.