Some things to think about in regards to supporting the emotional needs of your child clients during these unsettling and uncertain times. There are some hands-on ideas, suggestions, and interventions for children and their caregivers that may be useful as well.
Younger kids are more raw and more concrete than their older counterparts. They don't like ambiguity or looking at things through a "let's wait and see" kind of lens. They are more immediate, and black-n-white in their thinking. To help soothe worries, it's nice to start with VALIDATION of their feelings, almost to the point of restating their exact word choices. Let them know you realize how hard this must be for them. Wallow in this for a while, and let them cry or be angry or withdrawn, resisting the temptation to tell them that everything will be okay. This is a critical first step.
Next. With their "here-n-now" type of reality, it's good to let them know that they are not alone with how they feel, even amongst their own peer groups. Give examples of other kids, maybe your own kids, nieces/nephews, grandchildren, and how they are going through the same thing, normalizing it for the child. Be careful not to take away their reality, always listen to and validate how it affects them.
Anxiety/Depression often stem from feelings of helplessness. Ways to support this feeling with children, is to help them realize their may be things they do have some control over. Ask them what they ate for breakfast, or what type of clothes they have on today, shoes, hair items/gel, did they tie their own shoelaces, did they brush their own teeth, etc. Reflect back for them all the things they have control over and demonstrated that they can do. From here, you could begin to explain some aspects of the case that "you" are controlling, giving them a sense of transfer of control from you to them, letting them know that you will help them not feel so helpless.
For you, child clients, and caregivers. Explore using "Zoom" on your computer/laptop/iPad/smartphone. It just takes one person (adult) to have a free account, and then they can invite others to join. The child can set up Zoom visits (with caregiver assistance) all by themselves - with up to 3 friends all at once, using the free Zoom account. They used to have a 40 minute limit for the free account, but they have made it unlimited during COVID-19. All they have to do is look up Zoom on a computer and get a free account with just a login and password... it's so smooth and easy! Then, they'll see how there are places to click and set-up Zoom meetings with others, and send them an email request to join, with a link, date/time, and a meeting ID#. The recipients of the invite email will have the option to temporarily (for the visit) download Zoom after they click the email link, put in the meeting ID#, and then suddenly they will see the other person and themselves too! Sometimes you have to click the box with your name in it to have your face revealed, and to select "play audio." It's really great for conversation, book reading, game playing, and even showing toys/items/drawings, playing instruments/music, dancing, goofing around, etc. You can select a different screen View at the top right, Gallery view is my preferred one.
See about the use of yourself as a "penpal", or encourage the caregivers to set this up (if appropriate) with a peer, neighbor friend, family member, school mate, etc. Most public schools have distributed parent directories to all households, and some have digital access through caregiver portals. This may be a nice way for the parent to connect with another parent and see about a penpal arrangement (and/or a Zoom time).
You could ask your client to "teach" you about things they are doing with their time at home. Ask about online homeschool and have them "teach" you about things they "like" about it and things they "hate" about it. Use word choices that resonate with them. I always like to start with the bad things, because it gets them rattling on and on, and makes them get silly and laugh, breaking the ice. From there, you can move on to the good things going on and validate those, enabling them to see that even amongst the bad going on, some good is inherent and still exists. You could even give them a "challenge" for the next time you will be checking in on them, e.g. see if they can add one more thing to the positives, or move one of the negatives and transform it into a positive. You can play with the word "transform" with younger kids, giggling and imitating how that "transformer" would have to click around and change!