Something is wrong in your structure, in that you are duplicating same information from first table ( date, time fieldA ) into a child table. You should only be transferring the uniqueID from the first table to the second.
Then, any time you want to know the values from the first table while in the second, you display the first table's values through the relationship. This can be accomplished simply by placing the first table's values directly onto the second table's layouts.
I suggest that you provide a link to a simple example of your base structure with a few dummy records in it so we can see the 1:n relationship (you can upload a sample to a free site such as 4shared. I suspect you may have the requirements reversed. At minimum, we need to see a copy of your relational graph, key field names and what other fields exist in that second table (to provide us with example of its purpose).
If NumberObserved is your child table, my suspicions are increased that the structure isn't quite right.