Scripture of course does not address your question directly, so we need to look at scriptural principles and seek to make application from them. There is the overarching principle of selfless leading (loving head) and selfless yielding (loving helper) as men and women work together in God’s world (1 Corinthians 11:3).
Scripture makes general applications of that principle in the life of the church (1 Corinthians 14:26-40; 1 Timothy 2:1-15). We recognize from those sections of the Bible that God has entrusted the authoritative teaching and preaching of his word in assemblies of his followers to men.
Congregational leaders will need to study and apply scriptural principles when it comes to unique situations like the instruction of children with adult observers in a worship service.
A parallel question to yours is one that asks if such a practice is beneficial, constructive and wise (1 Corinthians 6:12; 10:23-24). That question takes us in a different direction. The entire emphasis of Christian freedom is not on what we can do. In selfless love for others, Christian freedom also underscores the choice of not doing something out of consideration for the consciences of others.
I would recommend reading a very recent restatement of “Male and Female in God’s World: A summary of what we believe Scripture teaches about being male and female.” That document, along with accompanying materials, can assist congregations working through questions like yours.