Unfortunately I have no information on Rilo. I do know it's a surname and in the past has occasionally been used as a given name. It's most familiar today as part of the band Rilo Kiley's name.
“She’s mad, but she’s magic. There’s no lie in her fire.” - Charles Bukowski
http://www.behindthename.com/pnl/147561http://www.babynames.com/namelist/9852886