When you see character meals that state that it will feature a particular character and "friends", that means that they other characters can change day to day. Those at 1900 Park Fare that have been seen lately are:
Alice in Wonderland, Tigger, Pooh, Eeyore, Bert, or the Mad Hatter. They vary according to availability.
Mary Poppins usually doesn't circulate through the breakfast, but acts as "hostess" in the lobby, coloring w/ the kids while you wait to be seated. I have also seen Bert there on the weekends.
When we went, Mary and Bert were in the lobby and Pooh, Tigger and Alice were circulating the tables. If you get to see Alice, she is absolutely THE BEST!!!