It all depends on whether Kathy and you are the subject or the object. Just as you would use "I" as a subject and "me" as an object, you would use "Kathy and I" as a subject and "Kathy and me" as an object. If you are not sure which to use, try it with just "I" or "me" first.

Here are some examples:

I will meet you at the station. ("I" is the subject.)

Kathy and I will meet you at the station. ("Kathy and I" is the subject.)

This has been such a rewarding experience for me. ("Me" is the object.)

This has been such a rewarding experience for Kathy and me ("Kathy and me" is the object.)

Kathy Marlowe's birth name is Kathy Maslowski.

No. Kathy is NOT married.

Kathy Dowdell's birth name is Kathy Antoinette Dowdell.

Kathy Najimy's birth name is Kathy Ann Najimy.