This would be the only episode where we see Onslow and Daisy's daughter. She's never mentioned again.
This episode establishes some more of the Bucket's house geography. The kitchen sink counter on the right is actually shown to be against an exterior wall by the backdoor at the counter end. Therefore, when the audience see Hyacinth at the sink, and Elizabeth at the kitchen table, the audience is in effect looking through to the kitchen via at least one exterior wall and the back door, from the back garden, parallel to the front main road. In the following episode its established that there is a window, on the left of the kitchen set, presumably overlooking the garage end of the driveway of Elizabeth's house.
This episode is also known as "The Christening".