@julie burton, I am so sorry to hear that you don't feel like you have the support of the senior pastor for Sunday school and children's ministry. Please know that I am praying for you and your ministry, and also for your congregation and especially the leadership to become aware of the importance of discipling children, and through them their families.
I think Carol and Audrey make good points above about reaching out to families directly. During the shutdown I was sending monthly letters with an assortment of seasonal lessons and little gifts to my preschool class friends (and some of the other families, too). I received positive feedback from a few families; but now that we are meeting again in person, all have thanked me for the encouragement and for helping to keep them connected to the church and helping them disciple their children. (The associate pastor had asked us to write a letter to our students early in the shutdown; I decided to keep doing it as my own personal unofficial project.)
I am glad your associate pastor seems to be on board. Maybe she or you can share some studies on the importance of offering ways for families to connect as well as reminding the leadership of baptism promises to come alongside parents in nurturing their children in the Word. Here is a link to some thoughts about children's ministry as a way to activate adult and family attendance (and you will find many more articles and ideas at that link, including some research numbers).
Praying for wisdom and creativity as you go forward! And if you want a bit of "in-person" encouragement and brainstorming, join us on Zoom next Monday.