We are expecting our second child, a girl, May 6. We have gone back and forth on naming her. Our first is also a girl we named Lilly Savannah and although we love it I regret not spelling it Lily. What we love about Lilly is it seems suitable at any age to us but still whimsical and cute. The only other name we considered for Lilly was Naomi but my husband hated it and still does.
My name is Andrea and my husband is Dan. This pregnancy we first decided on Ella Violet but I decided I didn't like Violet and Ella was too popular, his two favorites have been Lucy and Olivia. Neither seemed right to me but I do like them. After I vetoed Ella we settled on Molly Rose, which I still like but there is a little voice nagging me that its too cutesy. Other names on our list
Chloe too popular
Magnolia (Maggie) too cutesy
Juniper, I don't like Junie and I want a nickname for this one
Ruby, again not quite right
Penelope (Penny) too popular
Tallulah, husband hates
I think the kind of name we like is fresh and cute but can still mature pretty easily.
To me, many of the candidates sound SO CLOSE to Lilly: Lilly and Ella, Lilly and Lucy, Lilly and Molly all have so much in common. But then, I have trouble reading a book in which two characters' names start with the same initial, so I am not sure I am a reliable indicator of Name Similarity.
I think your choice of Molly is great. It repeats the -lly of Lilly, but the different initial and different vowel sound keeps it separate. I don't think it's too cutesy: I have no trouble imagining a college-aged Molly, a mother named Molly, a grandmother named Molly, etc.
If you wanted to tone down the cute, you could use a different middle name: Molly Margaret or Molly Samantha or Molly Caroline has more weight.
Another option for cuteness-toning-down would be Holly.
You've got Penelope (#252 in 2009) listed as being too popular, but Molly is #92 and Lilly is #117 (and the spelling Lily is #18). On the other hand, Molly has been hovering right in that area for DECADES, whereas Penelope is shooting up at an alarming rate (from #946 in 2001 to #252 in 2009, and I expect another big increase when the 2010 data is released next month). This makes a huge difference in PERCEIVED popularity, which I think is even more important than actual popularity: it may feel as if the name Penelope is suddenly everywhere, whereas Molly feels steady and not very common (as it should: at #92, the name Molly is given to only 1 in 576 baby girls).
Bridget (a little difficult to say with the surname)
I also liked Piper, but thought it might not work with the repeating -er in your surname, and also might be too much of a change from Lilly: Lilly seems more soft and feminine, and Piper seems more sparky and energetic. Similar problems with the name Paige, though to a lesser extent (and no -er, but I still don't think I like the sound of Paige Drucker). And I considered names such as Ivy and Rosalie and Calla, but wasn't sure you'd want to start a botanical theme (Holly is also botanical, now that I think of it).