Dependent Drop Downs

Hello,

I am looking to create a dependent drop down with a list I have create to an already created table.
I am aware that I should probably be using the OFFSET function, but I do not know how to reference the previously created table. This table was created by someone else and I cannot access the original file.

So if I have a list of Children, A, B, and C and the if A is selected it will lead me to A's specific table and so on with B and C.

I know I have to reference the cell with the chosen option as well, so should I use the INDIRECT function? I am confused.

Please help!

I have created an independent drop down list and choose from that. if I were to choose A, then the next cell would give me an option of the corresponding previously created table.
I also have a cell with the drop down box already created for the table I am trying to reference, would I be able to reference that cell instead of the table itself?