I love
Lydia, and since
Olivia is your dd's mn, I wouldn't worry about them being too similar. I definitely prefer it to
Liliana and
Leah (which are both lovely, but
Lydia is far better imo), and I love the sound of
Isabel &
Lydia as sisters. :) If it's popular in your area, you might want to reconsider if you're concerned about popularity. If not, I don't think it'll be number 1 on the charts anytime soon, but it could be getting more popular, for sure. Also, if your dh isn't very close to his aunt, or if you want to honor her, either way, I think using
Lydia is fine. I prefer it to
Lidia, which while nice has the word "lid" spelled out in it, which bothers me. LOL.
~
Heather~
