This little valentine card is an antique found in an abandoned house about to be torn down years ago. I scanned this valentine and dozens more and date them around 1914.
I chose 1914 a the valentine year because of the style of the bloomer outfits for boys and girls looks like it is from that period; and because some of the other valentine cards depict children dressed in World War I uniforms.
Checking Amazon to see if they sold old fashioned valentine cards, I found several but the one on the left most closely matching all the cards I have.