Mr$.$ Josh and Ms$.$ Lily are navigating the complexities of child support following their divorce. They have four children, all under the age of $18.$ Mr$.$ Josh wholly supports the second child, while Ms$.$ Lily wholly supports and lives with the fourth child. Mr$.$ Josh has full custody of their $22-$year$-$old eldest child pursuing a medical degree, and Ms$.$ Lily has custody of their $17-$year$-$old child studying abroad in Canada.

$1-$Considering the intricate family dynamics, calculate the child relief for Mr$.$ Josh and Ms$.$ Lily, taking into account the unique support arrangements for each child. $(15$ mark $)$

$2-$Further, analyse the child relief for Mr$.$ Josh and Ms$.$ Lily, considering the age and educational pursuits of their children.