The sibset is lovely but I agree with merrybells about full names. I've heard Lila on its own but Penny doesn't work very well as a full name.
Penelope came to mind but also Peyton, Persephone, Proserpina? And Liliana or Lilibeth with nicxkname Lila would be gorgeous.
Lila Reverie and Penny Tabitha
Lila Hermione and Penny Evangeline
Lila Gwendolen and Penny Imogen
Very cute! I agree with others about Penney.
I like Penny and Lila as a sibset! (Coincidentally, this morning I talked on the phone to both a Penny and a Lila) :)
Both names exude sweetness to me so together they are adorable :)