I usually consider the meanings behind character names, but not for this, which was weird. For Helena I wanted something old fashioned or uncommon that could be shortened easily, to better mimic Wilhelmina/Mina. Although meaning was less important, I did want to find a namesake that she could harken back to. Her parents would have named her after a saint so Helena was a good choice as it hit both criteria and that particular saint also brought in a slight motherhood angle (which was more important during her initial creation than it is now). Another bonus was that she was a Helen namesake, although less emphasis on a pretty-face/launching-ships part and more on the leaving-her-duty-and-husband/running-off-with-her-lover part. Her maiden name Rossi came up during a surname search of New York and Kelly just sounded nice and unassuming.
Stefan was a second choice name but a very close second. It only lost points because it’s harder to find a nickname for him, and I like options for nicknames. He was originally going to bear my friend’s last name but when I tried to find the meaning of it, she and her brothers were the first few hits on google and that made me all squicky. Ionescu was a surname of an almost forgotten acquaintance and once I remembered it it just fit. Wish there was a better reason that that.