Holly in first place! I love this name, it's on my list too. I think it works well for all ages. It is a classic name but not boring and not overdone.
Ruby in second place. Lovely name, again a great balance of classic but not overdone.
Maria third. There aren't many Marias around at the moment, maybe there will be a revival soon? Also loads of nickname potential, My grandma was a Maria and went by 'May'
I like Ella a lot, but unfortunately, it is so overdone. (That said, if you love the name, don't let the fact it's popular stop you!)
Grace in last place. Every other girl has Grace as their middle name. Of the Graces I've known (with Grace as their first name), all have been posh and a little bit spoilt so I have a bad association. But that is just personal bias.
Overall, all very pretty names. We have similar taste!