Yes, it's important for them to see you enjoy life and be happy.
Kids take their cues from you. They are super sensitive to your moods and it affects them greatly. So, that's why it's important to take care of yourself because otherwise you will be this stressed, anxious, snappy parent, which makes the situation way worse.
When I relaxed around my kids, it really changed things. Don't be a sad sack around them, and if you are feeling down, find some private space and process your emotions - whether through crying or binge watching something or whatever.
