How to nest blocks with text?

[bbsclient]

I am trying to create a block that contains text along with multiple child blocks. By default the text of the parent appears behind the child blocks. What is the best way to get the parent text to appear above the children.

block-beta
block:Parent["Parent"]
child1 child2
end

I was able to work around it slightly by adding spaces to force multiple rows of children but I wasn't able to get the parent text to be top justified using classDef with vertical-align:top.