On '30 Rock' this week, 'TGS with Tracy Jordan' celebrated Mother's Day with all of "The Moms" of the cast and staff during the big finale. That provided the perfect opportunity to bring back Anita Gillette as Liz's Mom, Patti Lupone as Frank's Mom (suspiciously under-used), Jan Hooks as Jenna's Mom, and of course, Elaine Stritch as Jack's Mom Colleen.
During the episode, Liz found out that her mom Maggie had "settled" for her husband Dick Lemon, instead of following her heart with her true love - Buzz Aldrin!
Maggie also let it drop that she had no choice - she had just finished secretarial school and had landed a job at Sterling-Cooper!
Fans of 'Mad Men' know that Sterling-Cooper is the name of the advertising agency at whic most of the characters worked - at least until the last episode of this past season.
For once, there was no over-splainin (suddenly the phrase "obergrupensplainin" popped into my head) about that being a TV reference to spoil it all. So for all intents and purposes, '30 Rock' and 'Mad Men' share the same TV dimension with no strings attached. (They did show that Matt Weiner, creator of 'Mad Men', was one of the writers on an episode of 'Bitch Hunter', but that had no further ramifications in connection to 'Mad Men'.)
I don't know how long Maggie Lemon worked there before the family moved out of state to Pennsylvania, but if Liz was still in NYC as a little girl and she visited her Mom at work, maybe she got to go up the block to visit Rockefeller Center where she would someday work. (Based on this picture from 'Mad Men', Sterling Cooper can be found around the back side of St. Patrick's Cathedral on the opposite side of Madison Avenue.)