NewRow to DataSet

Good-day,

I have a dataset containing two tables, in a Master-Detail type relationship.  I would like to insert a new row into the child table, but I'm receiving an error "ForeignKeyConstraint RelTables requires the child key values (There) to exist in the parent table".

Here is my code:

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//DataSet ds
DataRelation relate;
relate = new DataRelation("RelTables", ds.Tables["Parent"].Columns["Col1"], ds.Tables["Child"].Columns["Col1"]);
ds.Relations.Add(relate);

DataRow dr;
dr = Form1.DVM.DataSet.Tables["Child"].NewRow();
dr["Col1"] = "Hello";
dr["Col2"] = "World";

ds.Tables["Child"].Rows.Add(dr);
******************************************

Any suggestions would be appreciated,
Thanks for your time.