Thank you, Kirk, I was just going to post that reminder. I procrastinated too long last year, but I have bought my cards now.
My family also enjoy getting unique cards, so I like to buy them here, though card website's are handy in an emergency. The US Post Office also has a card sending feature, it came in handy when I needed to send a get well card in a hurry, and I was able to add the text I needed, all for less than £2.
For more details about the English history of Mothering Sunday, there is a link to information on
http://www.uk-yankee.com/calendar.html (Click Mothering Sunday)