Actually, the meaning is not "love child" as in the slang term for a child born out of wedlock but as in "beloved child."
-- Anonymous User 8/5/2007
I went to school with a girl called Masami who very recently had a daughter called Aiko. They had some difficulty choosing what to name their daughter and finally decided on Aiko, with the kanji for 'good-looking, quiet' and 'daughter, girl' [like in this link - http://kanjidict.stc.cx/japkanji.php?d1=on&s=%E5%A7%B6%E5%A8%98&max=50&exact=on&d3=on&d9=on&d15=on&d16=on. I don't know if the link will show up or if it will even work, but it's worth a go.] As far as I know, it's an uncommon kanji choice and I can't say I like it - it's pretty and unusual, but the meaning just seems a bit old fashioned, to me.